Facebook's newest feature, Nearby Friends, begins rolling out today. The opt-in app addition lets your friends know when you're close by, with the option to show your precise location on a map, if that's the kind of thing you want to share with your friends.
Is Facebook Places not sufficiently immersing you in the mundanity of your friends' lives? Try Nearby Friends, an app that plots their check-ins—past and present—on Google Maps. Just don't let any of them catch you using it.