Facebook Places Puts Foursquare, Gowalla on Notice

The Wall Street Journal's Walt Mossberg has been testing Facebook Places, its just-announced geolocation check-in app, which he describes as "a new, optional service for its 500 million members ... (it) allows you to check in to various places you go, and share that information with your Facebook friends, complete with maps and comments and the Facebook thumbs-up 'like' feature."

Although he's fairly positive about the beta version of the mobile service, which also allows you to locate other members of your network, Mossberg says Foursquare and Gowalla have more refined features, and laments Places' shortcomings such as "you can’t keep check-in notices off your Facebook page, unless you broadly block other kinds of status updates." Read his review for his other gripes and likes.

One of the more controversial features is that users can not only locate but be located, even if they don't want to be publicly tagged by their friends. Facebook Places product manager Michael Sharon tells the New York Times that Facebook's privacy settings will let users decide with whom they want to share check-ins. Users can also remove themselves after they are tagged, and there will be extra controls for minors.

Advertising isn't a part of Places at launch, but Facebook CEO Mark Zuckerberg made it clear at the press launch that ads and sponsorships will play a role eventually.