This is a networking site which has apps for most smart phones, and that requires you to move around. You get points and badges for go to certain check points, and you can even get deals if you go there enough.
A fun site that lets you compare book ratings with your friends and see what they are reading.
It’s probably more likely that you have heard of this site, but most people just use the streaming radio. The social network part of Last.FM is cool too, though. You can download an app your your computer and smart phone and it will link directly to Last.FM which will keep track of the number of times you listen to every song you listen to on your ipod and itunes library. You can then compare your music compatibility with friends and share music with them.
This site does what the facebook app Flixter tries to do, but better. The Auteurs is a social site dedicated to film, for more hardcore film fans.