There’s a tendency in the Twitter era for people to share copious details of their lives with online pals. One way to do that is through new mobile-phone services that let people share their physical locations using the tracking technology inside modern cellphones.
While these location-sharing services have some interesting possibilities, they also raise some disturbing implications for privacy — or maybe it just seems that way if, like me, you’re over 35 years old. Lately I’ve been testing a cellphone location-sharing service that I found simple, useful and non-creepy enough that I can imagine people thirtysomething and older using it.

Send a ‘Glympse’ to share your location
The free service is called Glympse, from a company of the same name that has designed it to share your location with friends and colleagues in small increments of time — glimpses, as the name implies, of your whereabouts. Glympse just released a test version of the service as an application for the G1, a phone offered by T-Mobile that runs Google’s (GOOG) Android operating system.
The company will release versions of Glympse for BlackBerry, Windows Mobile, iPhone and Nokia (NOK) phones in the coming weeks. Users can download the Glympse software onto G1 phones through Android Market, the online clearinghouse for applications for Android phones.
I used Glympse on an iPhone and a G1 and, for comparison, tried out a couple of other location-sharing applications, Google Latitude and Loopt. When you start the Glympse application, it identifies where you are on a map using a combination of location technologies in cellphones, including GPS satellites, Wi-Fi hot spots and phone towers.
Your location isn’t shared with others until you “send a Glympse” to someone. The software allowed me to send a Glympse with my location for selected chunks of time lasting anywhere from zero minutes to four hours. Picking zero minutes shared only my location at the moment of sending, while selecting four hours meant the recipients of my Glympse could track me for that period of time, wherever I went.
The sender of a Glympse can address it by entering a recipient’s email address, or a mobile-phone number for a text message. Recipients get a message with a link to a map on a Web page. A nice thing about the service is that it doesn’t require recipients to have the Glympse software, though the experience is richer when they do.
Sending a Glympse can be helpful anytime a friend, family member or colleague is expecting you. You can send a Glympse that lets a friend know you’re stuck in heavy traffic (although it’s wise to do that before you’re on the road to stay safe and, in some states, to avoid breaking the law). Parents can insist that teens send a Glympse when they go out for the evening.
Bryan Trussel, the CEO of Glympse, sent me several Glympses with short messages like “late lunch meeting” and “headed home” to explain where he was going. On the G1, I could see an icon representing Mr. Trussel moving around a map as he drove through the streets of Redmond, Wash., including his speed. I was also able to see traffic conditions, which would have been helpful if he had been running late. Glympse gave me a similar view of his location through a Web browser running on my PC. On the iPhone, the experience was more static, forcing me to reload a Web page to get a fresh view of Mr. Trussel’s whereabouts. Glympse says it will fix this so users of the iPhone can watch someone’s location in real time.
I encountered a bug with the service when I sent a couple Glympses to my own cellphone and that of a colleague — both BlackBerrys and neither of which had Glympse software. Both Glympses linked to high-level maps suggesting I was somewhere in North America, which wasn’t very helpful, even if it was technically accurate. The company couldn’t figure out what the problem was, and it eventually stopped happening for me too.
Once a Glympse expires, the service no longer tracks the sender’s location. It will show the sender’s last known location for 48 hours after the Glympse expires. Glympse may some day use your location information to target advertising to you, but the company isn’t doing that for now.
I’m far more comfortable with this form of finite location-sharing than the approach used by other services. Google Latitude lets you share your location to only a list of friends. It gives you the option of turning location sharing off or, through a “city level” option, it reveals only your general whereabouts. Loopt similarly allows you to set options to show, or hide your location from all or some online friends. A feature called Loopt Mix lists strangers you can send messages to in your general vicinity — many of whom seemed to be looking for romantic partners in my area.
Despite these controls, I easily forgot I was sharing my location with these two services. This might be fine for someone who enjoys being tracked down by friends during a night out on the town or is diligent about changing privacy settings when they want to go stealth.
I’m too lazy to manage my privacy so closely though. I don’t mind giving friends a look at my location, but only if I know the invitation isn’t open-ended.
- Email nick.wingfield@wsj.com.