LivingSocial is a social networking site that, unlike the MySpaces of the world, is more interested in its members sharing and cataloging their passions: movies, music, games, food.
Add iPhone apps to that list. A new iPhone-centric area of the site shows you what apps your friends, have tried, reviewed, and rated. You can then add your own rating, share your perspective, or purchase apps that look interesting. (One caveat: you have to manually create your list of apps yourself.)
Like Facebook, LivingSocial also has a free app available from iTunes. And the two sites are on good speaking terms: you can syncronize all kinds of info, iPhone-related or otherwise, between them.