Does anyone use Last.fm? I do and I LOOOOOOOVVVVE it! It keeps track of music you listen to on your computer so you know what song/artist you listen to most and how similar your music tastes are to the friends you add on Last.fm.
I love it because I find it interesting to see how I compare with people and sometimes it is surprising to see what you listen to most. It also lists artists' tracks and tells you what artists are similar so it is great to broaden your knowledge of bands and find more stuff you will like. I have started liking so many bands after finding them on last.fm! Also you can download some free tracks every so often, listen to streaming music and watch videoclips.
It works best if you listen to music on your computer a lot rather than cds or off your mp3 player (but there may be an extension for getting data from certain mp3 players to add to your listened tracks and stuff).
If you have it post you username here so we can add each other and compare taste! If you want to join it's free and you just dl the software for whatever music player you use. Go to: http://www.last.fm/home
My username: Tortus333