The crucial feature of Facebook photos is that, by default, friends can tag users in pictures without the users confirming that the pictures are actually of them. So with the new layout, friends can decide what pictures show at the top of a person’s profile. And for the more creative, they have five concatenated pictures in which to do so.

Facebook users are already having fun with this option, pranking each other to show inappropriate pictures and silly sequences of words. BuzzFeed ran an NSFW example of this earlier this week, with one of its users apparently pulling the suggested prank on the Facebook of a fellow named Trent Reznor.

Users worried about their profiles being hijacked for everyone to see can change their privacy settings. (For instance, a user can limit who is allowed to see other people’s photos she is tagged in.)

Top image by BuzzFeed user shwagner.

Please see the disclosure about Facebook on my ethics page.

Still, there are ways to increase your chances of making stuff go viral. Or at least improve the performance of stuff that is going viral.

That’s sort of the premise behind BuzzFeed, Jonah Peretti’s New York start-up. Last night, Peretti put on a presentation that was half sales pitch and half how-to guide for aspiring viral-content makers. You should click through the whole thing, which is quite entertaining and embedded at the bottom of this post. Sample:

Note that some of Peretti’s presentation focuses on how the Huffington Post maximizes its traffic. That’s because Peretti was a co-founder (or early hire, depending on who tells the tale) at Huffpo, and crucial to setting up the site’s tech-savvy strategy.

Many people still think of Huffpo as a political site fueled by celebrity bloggers, but the site’s real recipe for success is its focus on real-time traffic analysis. Huffpo doesn’t talk about this much in public, but slide No. 18 gives you an idea of what the site is doing.

And, because Peretti knows what he’s doing, these slides are almost certainly going to become a Web pass-along. The Jews vs. Mormons analogy he starts on slide No. 29 pretty much guarantees that.

Jonah Peretti Viral Meetup Talk

Here’s a prime example, via an unnamed magazine’s photo spread. The camera attached to that Betamax, by the way, clocked in at a featherweight five pounds.

Apparently, if you want to think about the growth of the Huffington Post as a culinary dish, perhaps today’s replacement of CEO Betsy Morgan with longtime online media powerhouse Eric Hippeau might appear under the Emeril Lagasse cooking cliché: Let’s kick it up a notch!

Both co-founders of the online media site, Arianna Huffington and Kenneth Lerer, said as much in interviews I did with them this afternoon, after news of the change got out–even as they praised Morgan for the strong work she had done in the 18 months she had been in charge.

“The deal is that we simply have been growing so fast that we needed more firepower to accelerate in expanding the site and monetizing it,” said Huffington, who is also editor-in-chief of the Web news site (and pictured above).

“Things are going great, but things could be going even greater,” added Lerer, who is chairman of the Huffington Post, noting that a more experienced exec was needed at this juncture to take the business to the next level.

“Eric is a peer at all the big companies we need to partner and deal with…and right now, while things are difficult in the economy, is the time when you can really build a company and we had to take advantage of that opportunity.”

So, ipso facto, Morgan was out in favor of Hippeau, who was the key player in the $5 million investment in the Huffington Post by SoftBank Capital in 2006.

Hippeau is a director on its small board, which also includes Huffington, Lerer and Oak Investment Partners’ Fred Harman. Morgan will be vacating her board seat.

Oak recently added $25 million to the funding kitty at the Huffington Post, money that Lerer and Huffington said had not been used yet.

But it soon will be, both noted, with the site expanding aggressively into the local arena, investigative news and verticals such as tech.

It is all being done to build on what has been a strong traffic year for the Huffington Post, which claims it has over 21 million unique monthly visitors.

Nielsen Online has pegged that at the lower figure of 8.9 million, but reported that the Huffington Post was one of the fastest-growing, year-over-year news sites.

Despite that, the site still has not been regularly profitable, said Huffington, despite doubling annual revenue–mostly in advertising–to what some estimate to be about $8 million in 2009.

Hippeau (pictured here) has a lot of experience working at a panoply of early online media businesses, including as CEO of Ziff-Davis.

He has also been a longtime Web investor, pushing for SoftBank’s early investment in Yahoo (YHOO), where Hippeau remains a board member.

That should not present a conflict for Yahoo, said Hippeau, which had a short-lived publishing partnership with the Huffington Post.

Hippeau, who has been a managing partner at SoftBank, will become a special partner and adviser to the investment firm. In this capacity, he will continue to work with three start-ups–Buddy Media, BuzzFeed and ThumbPlay.

Hippeau, who is now diving back into an operating role for the first time in almost a decade, said it was hard to pass up the chance to run the New York-based Huffington Post.

“I could not pass such an opportunity, especially with the explosion in the delivery of the news and opinion on the Web,” he said. “This is really the place to build the next really big brand.”

To get to that level, Hippeau said that a lot of things have to happen at the site going forward.

“Clearly we have got to make the revenues commensurate with traffic of the site and size of the opportunity,” he said. “At the same time, we have got to make sure we are very community-focused and using all kinds of new tools to increase engagement.”

Hippeau noted that journalism was changing radically, and “what people want to know is what are people thinking and how can I contribute and we are just at the beginning of this phase.”

Of particular interest to him are real-time data and real-time communications–on sites like Twitter–and the growth of smartphone usage.

“We are getting into a situation in the U.S., where it is so much easier to access all kinds of information and so much more portable,” said Hippeau. “Everyone has talked about convergence for a long time and it is finally here and we are poised to take great advantage of that.”

The moves at the Huffington Post were first reported by paidContent.org.

Huffington appeared onstage at the recent D: All Things Digital conference with Washington Post (WPO) publisher Katharine Weymouth.

Here is a highlights video of the interview I did with them: