I just stumbled upon the famous http://last.fm/ website - really great website that tracks down your audio preferences. Useful to show off your stats and music to your friends.
It's unfortunate that many people practically show off the origin of their (illegally downloaded?) songs, take a look: http://www.last.fm/search?m=all&q=www.
Makes you think again before posting your audio along with your personal information... ;)