For those who aren't in the know, Last.fm is a scrobbling service (no idea where the name comes from), which tracks what music you play, how often. Now most people wouldn't care, but for music junkies this is a bit of a treasure chest. iTunes tends to do this as well, but in a not-as-intuitive fashion nor does it retain data after a reinstallation.
If you are a scrobbler, post your profile URL here. Mine is www.last.fm/user/rmatin/
I just found out that they provide a image-based charts service as well!: