Last.fm is a UK based social networking and internet radio site founded in 2002, with over 30 million active users. Last.fm gives users the opportunity to create custom profiles and build radio stations based on their musical interests. Using music software called "Audioscrobbler," last.fm builds a profile of each users interests by recording songs they listen to. From there, the site is able to recommend new artists to users as well as create a list of musical neighbors with similar tastes. The site is a great platform for listening to and discovering new music of all genres.