Tossing in something completely unrelated - check out Audioscrobbler. You can install a plug-in for your favorite audio player, like iTunes, and it will upload your listening habits and build a history. So you can look at graphs of which artists and songs you listen to, find others with similar interests, etc. Really quite exhibitionistic and voyeuristic. I've been using it since earlier this year. So now you can poke fun at my musical tastes.
Feedback is welcome. :-)