yea hat.. its last.fm
click my sig and it brings you to my profile that lists my recent songs, charts and graphs of what i listen to etc..
all you do is download an audio scrobbler program (i downloaded isproggler) you put one .exe file in your itunes folder and the program itself in your start-up folder.
im using itunes on xp.. its really easy.. if you need help their is a forum(where i downloaded isproggler and its latest versions like every month

.. but they have been getting better about it)