Transmitting personal data between applications doesn’t have to be for nefarious purposes. In fact, it’s often something that we users like and encourage — when we sign up for new services, we often volunteer our credentials from Facebook, Twitter, LinkedIn, Instagram and elsewhere.

Connecting these accounts means we don’t have to type in our personal information yet again in order to try some new thing; we can see which of our friends already use it, and we can cross-post our activities so we’re not constantly manually updating all these different networks.

You don’t have to try very hard to imagine why companies like this.

Singly offers this whole account-connection process as a service to developers, so they can get “merged, normalized and de-duplicated social data” aggregated together from at least 10 different APIs. This is similar to how developers might connect to Factual to get access to public datasets about places.

Singly is still in its very early stages; CEO Jason Cavnar told me that today just three applications are being built using Singly, and they are too young to name. But examples of apps that he thinks would benefit from Singly include any service that is built as an interface on top of existing information about users — like Mint, Flipboard, Showyou, Highlight, Sonar, Greplin, CloudMagic, Tungle, Nimble and Timehop.

Beyond social data, Singly is entertaining visions of connecting to credit card companies, utilities and other sources, all in the name of helping users dole out access to their personal data.

Singly started life as “The Locker Project” and attracted particular interest because co-founder Jeremie Miller founded the open source instant-messaging protocol Jabber. The company continues to open source its data-connection work, while offering it as a service to customers.

Early on, Singly had focused on hosting applications as well, but now it plans to be primarily an API provider, Cavnar said.

New Singly angel investors, along with Foundry Group, include Robert Stephens, the former CTO of Best Buy; Federated Media’s John Battelle; Esther Dyson; and Roger McNamee. Previous seed investors included Venrock, True Ventures, PivotNorth Capital (Tim Connors) and Freestyle Capital.

At the St. Regis hotel in San Francisco, Mark Zuckerberg says young people say email is too slow. They prefer Facebook or SMS.

Zuck: IM or SMS are much simpler, and people want lighter-weight things that they can use all over the place. So we need…a modern messaging system.

350 million people actively use messaging on Facebook, in part because it’s really simple. Four billion messages are sent per day. This is “private, private sharing.”

Next-generation messaging would be: seamless, informal, immediate, personal, simple, minimal and short. (Those are a lot of synonyms, no?)

“This is not email. Email is one way that people will use this system, but it’s not even the primary way we think they will use it.”

Now a three-panel slide is up showing the key topics of the announcement–”seamless messaging,” “conversation history” and “social inbox.” Zuckerberg promises, “We can do some really good filtering for you to make sure you only see messages you really care about.”

Zuck brings on Andrew Bosworth to demo the product.

So this is actually a relaunch of the “Messages” tool. Not email-specific. Takes all correspondence between two friends and puts them in one place.

Everyone gets an @facebook.com email address with their username. “As much as we’re providing an email address, the system’s not email,” says Boz–more like instant messaging.

Boz uses convo about dinner plans as an example, with messaging across different platforms, including IM on Facebook, email, iPhone notifications, etc. The example restaurant is Piccino in San Francisco, where, fun fact, I was for a short time the Foursquare mayor. No longer though.

Integrates with Jabber, IMAP and one more I missed. (Sorry, first time liveblogging with this tool!)

Boz shows the history of Facebook messages with his girlfriend of the last four years. But doesn’t include their instant messages and other communication. Individual messages may not be profound, but collectively they provide a narrative about someone I care about, says Boz.

Facebook rebuilt infrastructure for this project, because it’s especially important that messages don’t get lost.

Instead of Cassandra (which FB created for email search and then open sourced), the company chose something new: HBase. They also used Haystack, Thrift, ZooKeeper and memcache.

This is the biggest engineering team Facebook has ever put together for a launch–15 people, Boz says.

Users have three categories: 1) Messages: Conversations with actual people. 2) Other: Email lists and the like. And 3) Junk.

The big idea is “picking up where you left off” no matter what device or medium.

This project has been in the works for the last 15 months.

Zuck: “This is not an email killer. This is a messaging system that includes email as a part of it. We don’t expect anyone to wake up tomorrow and say, I’m going to shut down my Yahoo account or my Gmail account and switch to Facebook.”

(Read: You silly press, we’re not competing with Gmail, we’re bigger than Gmail!)

Rolling out slowly over the next few months, starting with an invite system (ha! how Gmail!).

Oh, about IMAP: No support yet, so users can’t synch with other email systems. But Facebook wants to add later.

Interesting: Facebook messages won’t have subject lines. You just have a single messaging history with each person.

If you have been interacting with someone through email, then we’ll send replies back to email. You can indicate that you want a message to go directly to their phone. If you’re online, you get a message as an IM.

Boz: This is the end of “BRB” or “GTG.” Follows you wherever you go. (Sounds ominous when you say it like that.)

Question from audience: Will you add voice or video?

Zuck: For now only SMS, IM, email and FB messages–all are text. “We think this is a pretty big step by itself, and one we just wanted to take before we get started on the next set of things.”

Question from audience: Will you have contextual ads?

Zuck: Yes, ads work the same as on the rest of Facebook, but not targeted specific to content in a message.

Zuck on Gmail competition: “They have a great product. Email is still really important to a lot of people. If we build a great product that people want to use, then people will use it.”

Question from audience: Can users go off the record like in Gmail?

Boz: Users can delete any message.

Zuck: Off the record like in IM doesn’t make sense because users may be receiving messages in a different way than you send them. If someone gets something in email instead of IM it would be unnatural to have it off the record.

Question: How will this treat communication with people who are not on Facebook?

Boz: You can communicate with whoever you want to, and will have access to all that history of the conversation.

Zuck: If you’re not a part of the FB system and outside the social graph, your emails to FB users will go into “Other” folder to start off with, rather than the main. Once the recipient says you’re an important person, you’ll go into the main folder.

Question: What about silly joke emails from your mom? Can you filter those?

Zuck: There’s only one thread with every person.

Question: What about Facebook employee email addresses?

Zuck: “After a long discussion, the Farm Bureau has agreed to give us fb.com. And in the terms of that we have agreed not to sell farm subsidies.”

Facebook hasn’t mentioned this, but Microsoft just emailed to make sure people know they’re involved.

“As part of Facebook’s new messaging system: http://apps.facebook.com/facebooklive/ –Microsoft is integrating the Office experience. Over the coming months, customers will be able to access and share Microsoft Word, Excel and PowerPoint documents as attachments to their Facebook messages. Sharing new ideas, key points of inspiration and important information just got easier–even when the need to access or share that content strikes in the middle of your latest status update.”

Question: Can you fill in the blanks of associating email addresses with Facebook friends?

Boz: Not yet, but it’s imaginable.

(Uh-oh–how is this going to work when people have multiple contacts for themselves?)

Question: Storage?

“If you’re a good user, you have no concern. For people who try to find limits, they will find them.” Another ominous comment from Boz.

Okay, they’re cutting us off.

Here’s the Facebook blog post on the announcement.

Please see the disclosure about Facebook in my ethics statement.

AOL’s AIM started out with enough popularity to freely ignore the need to integrate with other programs; now, it can be argued that AIM retains its relevancy by operating with other messaging programs like Google‘s Gmail chat and Apple‘s iChat. Other IM clients paired up with one another to increase usability, like when Microsoft and Yahoo became interoperable over two years ago.

But nowadays, social-networking offerings — like leaving messages on Facebook walls and receiving Twitter “tweets” from friends — compete with traditional instant-messaging programs. And advanced technology in mobile devices has helped these chats move from desktops to iPhones and BlackBerrys, where conversations can continue on-the-go, using mobile applications.

Three free programs — Meebo, Adium and Digsby — work by consolidating numerous messaging accounts into one combined program.

This week I tested three free programs that seem to acknowledge the fading star of isolated instant messaging, as we once knew it. Meebo, Adium and Digsby work by consolidating numerous messaging accounts into one combined program. Some of these include social-networking integration or even built-in email notifications, turning the service into a one-stop shop for online communication. The result can save people from choosing one IM system over another.

All three of these programs are straightforward and work without much effort or instruction. They require users to enter the user names and passwords to log onto each IM account, which may make some people uncomfortable, even though each site explains its privacy policy. Of the three, Digsby offers to integrate with the greatest number of programs all at once, including instant messaging, email and social-networking accounts. It also lets people handle email by deleting or sorting it directly in the IM window, which neither of the other programs does.

But Digsby isn’t yet usable on Macs or Linux, and Adium (the second-best offering) is available only on Macs. When used with the correct operating system, these programs perform as promised, easing communication overall and saving people the hassle of logging into various accounts — or missing out on chats with friends because of not signing into certain programs.

Meebo, www.meebo.com, is the only one of these three products that is completely Web-based. It works on all major browsers, including Internet Explorer, Firefox and Safari, and doesn’t require any installation — a plus for those who would like to be using instant messaging in the office but aren’t able to install software on corporate computers. It can log users into one of six messaging programs simultaneously, including Yahoo, Microsoft, AIM, Google, ICQ and Jabber.

I signed onto three instant-messaging accounts at once on Meebo by entering the username and password for each and selecting one overall “Sign In” button, which logged me into each program simultaneously and displayed all of my contacts in one condensed panel. Meebo can be configured to automatically launch within Firefox if a Firefox extension is downloaded.

Meebo.com is also usable on the iPhone and iPod Touch, allowing people to log into multiple accounts simultaneously from their mobile device. As of now, neither Adium nor Digsby has an application that allows it to work with the iPhone or iPod Touch.

Digsby, www.digsby.com, was a cinch to set up on my laptop, which was running Windows Vista. It walked me through the steps of adding accounts from instant-messaging programs, email accounts such as Gmail and Hotmail, and social-networking sites such as Facebook, MySpace and Twitter. Digsby works with IM and emails accounts from AOL/AIM, Yahoo, Microsoft and Google. Jabber, ICQ and Facebook chats also work with Digsby, along with IMAP and POP email accounts.

Once added, all of these accounts are represented in one clean panel. These consolidated communication programs saved me many extra clicks on my computer over a weekend, and I easily chatted with friends while checking messages. New emails received in my Gmail account were visible in a preview panel that popped up when I moved my cursor over the email account name. Right within this email preview panel, I could delete or archive each message; I was also able to mark a message as read or report it as spam. I performed all of these email tasks without opening my Gmail account in a browser or email client. Shortcuts in this preview panel labeled Open, Compose and Inbox sent me to my browser to perform these more-involved tasks.

This in-line functionality also applies to other email accounts, according to Digsby. But though I could see a tally of newly received Hotmail messages in my Digsby preview panel, these messages weren’t as interactive as those received in my Gmail inbox.

Digsby also tracks Twitter alerts and timelines, as well as Facebook newsfeeds and alerts — including posting notifications in your Digsby panel whenever someone “friends” you on Facebook.

Adium, www.adiumx.com, wins points for cuteness. The downloaded program is represented by a goofy, green duck, which plops itself in the Mac operating system dock and closes its eyes when not in use. When new messages are received via Adium, this duck flaps its wings until you open the message. The Adium user interface incorporates sleek visuals, such as status windows that gracefully float above user names whenever a cursor moves over these names.

Adium works with AIM, ICQ, .Mac, Jabber, Google Talk, Windows Live Messenger and Yahoo Messenger. Adium supports new email notifications for some accounts, but doesn’t enable reading or sending email within the program. Instead, it offered to open my account via the browser or using Microsoft Entourage on the Mac. Social networking is limited to MySpace IM on Adium, though the next version will support Facebook Chat.

Adium organizes multiple conversations using tabs stacked at the bottom of a chat window. Icons line the top of each chat window, such as a file icon for transferring files and a lock that switches a conversation to be encrypted and off-the-record. Any conversation that isn’t designated encrypted is automatically stored in a table of Adium transcripts, which can be sorted by To, From or Date. Transcripts can be sorted using rough timelines like “within the past two weeks” or “since yesterday.”

I saved myself time and mouse clicks by using these three consolidation programs, though I preferred Digsby in the end because of its intuitive email integration. These programs will help to take down the instant-messaging barriers that have become turn-offs over the past couple years, and may better integrate IM with the social networks and mobile devices that are on the rise.

Edited by Walter S. Mossberg

Write to the Mossberg Solution at mossbergsolution@wsj.com

Just use an Internet-based service so that you can chat from a Web page without having to install any software, which might be blocked by a firewall. I tested two such services: Meebo at www.meebo.com and KoolIM at www.koolim.com. Both are free.

These services let you simultaneously log in to multiple IM accounts — and communicate with people with various services. If you have a friend who uses Yahoo Messenger, for example, and another who likes MSN Messenger, you can chat with either.

Another plus: Meebo and KoolIM are far less vulnerable to viruses than downloadable applications. They’re also more efficient, saving users the hassle of installing multiple programs on a computer. This is especially handy for people with old computers that slow down when running several applications.

Meebo has a well-designed, sleek interface that makes it appealing to even the least tech savvy. From its home page, you simply sign in for different IM services—MSN Messenger, Yahoo Messenger, GTalk (or Jabber) and AIM (or ICQ). Your buddy list will be combined automatically. You don’t have to register, but if you do, you get perks such as a single sign-on for all of your accounts, and the ability to share files, save chat logs and store conversations.

I tried Meebo on my work Windows PC and my iBook at home, and it worked well on both. To start chatting, you just log in to any of the IM services by entering the screen name and password you already have with a service, or by picking a new name, password and services. Your buddy list will appear in a window on the right side of the page, with each name marked by an icon denoting the service the person uses. Once in your buddy list, you can add or delete a contact, message or join a group chat.

The service also offers MeeboMe, a way to chat from your own Web site. Bloggers can use this to start a conversation with site visitors who log in to their Meebo account. It also shows how many users are on the site at any time.

But Meebo, like most such Web services, lacks the ability for audio and video chats — basic features on installed IM software. If you’re used to plugging in a Webcam and headgear to chat with friends, these services might not be for you. Meebo also doesn’t have the standard send button that’s on installed IM software. Instead, you press a key on your keyboard.

Sharing files using Meebo is tricky, too. Only Meebo account holders can send files; although anyone can receive them. When I sent a PDF file to my friend on her installed MSN Messenger, she received a message and a link that rerouted her to Meebo’s home page with no further guidance. When I sent her the same file after she logged in to her MSN using Meebo, she could open the file.

KoolIM also connects users to multiple IM accounts from one Web page. It gives you the option to create an online account, so you don’t need separate log-ins for each IM service you’ll encounter.

You can select an embedded or a pop-up version of the service. The embedded version shows your buddy list and messages as windows tied to a Web page, while the pop-up version lets you move the windows around the screen. You can choose to display all of your buddies or only the ones online. In your buddy-list window you can add and delete names and log in to or out of a service.

I didn’t like having text ads appear at the bottom of the IM window in KoolIM, or the fact that, unlike Meebo, there isn’t a time stamp on messages to tell you when they arrived. It also doesn’t allow you to send files, as Meebo does. And it doesn’t let you save conversations or chat logs. KoolIM’s lack of some of these basic features might make it less appealing to consumers, especially those who ponder swapping it with their desktop software.

I preferred Meebo, but both services are good alternatives to installed IM, if you’re willing to do without audio and video features.

Walt Mossberg is on vacation. Find all my columns and videos online free at the new All Things Digital Web site, http://walt.allthingsd.com.

• Email me at Sarmad.Ali@wsj.com.

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about alternatives to instant messaging at work, what to look for in an inexpensive PC and using Macs to make trades.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

My company has banned us from using instant-messaging programs on our work computers, claiming they are a security threat. Is there an alternative way for me to keep using instant messaging, which I consider a useful business tool?

Yes. You just have to use a service that replicates the functions of instant-messaging software inside a Web page. That way you aren’t downloading an instant-messaging program onto the company’s computer, you’re simply using the Web browser already on that computer.

I’ve recently seen a cool new Web service of this type called Meebo, at http://www.meebo.com. It’s only 11 weeks old, and it’s still in testing, but it enables users to sign into four different instant-messaging services — Time Warner’s America Online’s AIM (or ICQ); Microsoft’s MSN Messenger; Yahoo Messenger; and Google’s GTalk (or Jabber). You even can log on to all four simultaneously and see a combined buddy list. Meebo is basic and hasn’t yet added fancy features like file transfers, but it works well on Windows PCs and Macs. And, it’s very slick. You even can move the message and buddy-list windows around within the Web page.

If the Meebo site won’t come up on your company computer, try the secure version, at https://www.meebo.com. If your company blocks this, too, I suspect it just hates the idea of instant messaging at work for reasons that go beyond security.

How can you suggest that people consider buying a Macintosh now when Apple Computer will be coming out with all-new models based on Intel processors starting next year?

With any digital-technology product, the pace of change is so rapid that there is always a newer, supposedly better model on the horizon. But people buy these products when they need them. If you wait and wait, you lose the use of the new computer or other product in the meantime. And the next model may be flawed or otherwise unsuitable.

My recommendation last week of the best desktop computer on the market this holiday season, the Apple iMac G5, was meant for people who plan to buy a computer this holiday or within the next few months. Apple’s changeover will be gradual; there is no indication when the iMac G5 will be replaced by a Mac with an Intel processor. It could be as late as 2007, according to Apple’s public statements. There is no way to know if a future Intel-based model will be better or less expensive.

In addition, current Macs will remain highly useful for years even after the Intel models arrive. Makers of software and peripherals are highly unlikely to restrict their products to Intel-based Macs, which will be few in number compared with the tens of millions of Macs based on the current design. Apple has devised a system for creating software that runs on both designs.

I would like to purchase a PC for my mother but do not have much money to spend. All she uses it for is email really. But I think if she had decent processing speed, she’d surf the Internet more. What PC would you recommend that is the least expensive, works with wireless Internet technology, and has decent processing speed?

The least expensive PCs are bargain-basement Windows desktop models. I haven’t tested these machines lately, but almost any of the sub-$500 desktop models should do the trick for these simple uses. You likely will have to pay extra for wireless Internet connectivity, since most desktop computers — even costly ones — don’t come with that feature, which is meant mainly for laptops. Also, make sure your bargain model has security software, a CD drive, and speakers — some don’t. You may have to add those features at extra cost.

As for “decent processing speed,” your implication that fast processors are needed for Web surfing is just plain wrong. The slowest processor on the computer-store shelf is more than powerful enough to handle Web browsing. If you have any extra money to spend in your tight budget, don’t spend it on a faster processor. Instead, make sure the memory is at least 256 megabytes, or 512 if you can afford it. That will have a bigger effect on Web performance.

In your favorable review of the new Apple iMac G5 computer last week, you said it may be the wrong choice for day traders. Why? Are Mac owners unable to trade stocks?

Although I believe Apple’s Macintosh computers and its Tiger operating system are superior to Windows computers today for mainstream consumers and small businesses, I have long advised that there are some niche groups for whom Windows is still the best choice. This is mainly because the Mac can’t compete with Windows for cutting-edge games and niche software.

The biggest examples of people who should stick with Windows are heavy-duty game players, or users who rely on specialized Windows software provided by their employers. I mentioned day traders in this list, because heavy traders sometimes rely on special software available only for Windows, or on Web sites that work best in Windows.

But I was speaking only about the most intense, full-time, stock traders. You certainly can buy and sell stocks on a Macintosh, using the popular Mac Web browsers, and many people do.

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Because of the volume of e-mail I receive, I can’t routinely answer individual questions by e-mail, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.