I'm sure some of you have an account there, but for those who don't. Why not sign up?
Last.fm is a pretty cool thing. You download the "Scrobbler" and you listen to your songs and it bascially says "you listened to this song some 20 minutes ago before this song 27 minutes ago" and it also tallies up your weekly plays on how many times you've listened to that band/artist in the form of a top 10.
Example:
1. The Beatles - 25 times
2. Iron Maiden - 20 times
3. Creedence Clearwater Revival 19 times
and so and so forth. It also has different charts (monthly top tracks, or how many times the artist been played overall)
it's pretty cool.
Here's mine. http://www.last.fm/user/GilmoursAngst
If anyone has any trouble figuring it out, let me know.