I just signed up this week but I think it's great. It basically tracks your music listening habits, songs, artists you listen to most...anyway I'd be interested to see what other cpers have on their playlists....if you haven't signed up it only takes 2 minutes...
www.audioscrobbler.com
You can view me
here.
BTW any metal you may see on there is more than likely from my roommate using my WMP.