Where Would You Be Without Facebook?

Facebook already knows what you like, who your friends are, what you're thinking right now, so what the hell does it matter that it knows where you are too, right? The king of social networks has finally revealed its much-anticipated location-awareness features. Facebook Places will let users with Facebook apps on their mobile devices "check in" at various locations to let their friends know they've arrived. It sounds very similar to existing networks like FourSquare and Gowalla, except for the small detail that Places is backed by a network with more than half a billion members.