Sign up for a free tunelog account. You will be able to dump in all your music usage and collection meta-data.
We've got a few tools to help do this automatically (iTunes PC, WinAmp PC, and Pandora are currently supported). Then, every time you play a song anywhere, it'll log it here. You'll be able to see all sorts of stats about your music and playing history and patterns. You can see what your buddies are playing, what they've got to say about their music, and find new stuff for yourself.
And coming very soon: music previews of all the songs and some awesome revenue opportunities for you...and you won't have to lift a finger.