I'm sure most people are familiar with it by now, but last.fm has a plugin that tracks your listening habits through programs like Winamp and iTunes (including ipods). It also has a radio station that you can customize slightly - unfortunately, if you're not in the US, Germany, or the UK, there's a fee.
Feel free to post your profiles!
http://www.last.fm/user/kimpy
Feel free to post your profiles!
http://www.last.fm/user/kimpy