I used to use this a while back and rediscovered it a few weeks ago.
It's an online site that with plug-ins that track what music you listen to and transmits it to your online profile for all the see. If you use the website (I don't) you can listen to a radio on there that plays music that is recommended by other people who listen to the same bands.
Also, you can have these chart things made that list and update what you've recently listened to in a forum signature/facebook/whathaveyou
I use it as well, my profile is here and there's a Neocolours group here. I love this site, charts and stuff really fascinate me so it's perfect. The one problem I have about this is that it makes me obsessed with tagging my music correctly.
I'm on it too, my name's Spivvers. It's quite fun seeing what you listen to most, but I have no idea why fall out boy are so high up the list. I don't even like them anymore =/
