Find My Phone, part of the new iCloud bounty, works just like Find My Phone. Only for friends. The app will pinpoint your contacts are on a map (if they permit it), allowing unprecedented impromptu hangouts and creepy stalking sessions.
This could be really awesome! Instead of having to bother with directions, especially if you're in an unfamiliar part of town (or town altogether), just let iCloud do the work. To me, it looks exactly like Loopt—back when people still used that, and before it became awful. Think of it as the social intimacy of Foursquare, minus all the "You'll never guess where I am!" geolocational penis-stroking and gameification. There are some neater features to prevent you from oversharing though. According to GDGT, the Find My Friends app will let you set location sharing blocks of time, so at the end of the day, location sharing will stop automatically if you so choose to. This will also be a boon to overprotective parents around the planet. [Find My Friends]