I signed up for an account at Last.fm and downloaded and installed the XMMS plug-in. (I manually downloaded the plugin from their site, and then thought to check Synaptic. Sure enough, it was in the Ubuntu repository!)
It’s pretty cool so far – after listening to only two or three different artists it already had Weezer at the top of the recommended list for me, and I’m a huge Weezer fan. It will be really interesting to see it when it really kicks in with other users in addition to just figuring out my listening habits.
If you’re really curious about my musical tastes, you can see my Last.fm user page here.