Audioscrobbler builds a profile of your musical taste using a plugin for your media player (Winamp, iTunes, XMMS, foobar2000, etc..). Plugins send the name of every song you play to the Audioscrobbler server, which updates your musical profile with the new song. Every person with a plugin has their own page on this site which shows their listening statistics. The system automatically matches you to people with a similar music taste, and generates personalised recommendations.
If anyone wants to check what I’ve been listening to while at work (or my prefered coding music), just click here.