Where do you usually find out about a new book to read, a new song to listen for or even a game to play? I think most of us would say we find new things through our friends and social interactions. LivingSocial, a DC-based startup created by the Ruby on Rails development shop Hungry Machine, is looking to help with similar social recommendations. Started as a Facebook application, LivingSocial offers a handful of vertical recommendation sites (books, food, music, movies, beer, and games). Leveraging the Facebook social graph LivingSocial claims to have 6.4 million beta users, who have collectively reviewed nearly 80 million items since February.