http://www.musickum.com
You should all check this out, it gives comparative statistics by-user-tag for what you've been listening to lately compared to 3 months ago. Also has a fancy-ass pie chart that goes with it.
And for those that really care about their music superiority, a so-called "Open Mindedness Calculator" that gives you a score of how 'open-minded' you are, but this feature is a piece of junk.
Userdata for 15.09.2008, (comparative data from 25.06.2008)
Tracks*: 6591 (4981)
Fav. tag: 9 (9)
1.
Hip-Hop - 8.73% (11.21%)
2.
experimental - 7.30% (5.63%)
3.
indie - 6.25% (7.26%)
4.
rap - 5.75% (8.23%)
5. folk - 4.74% (4.70%)
6. singer-songwriter - 4.35% (4.76%)
7. post-punk - 3.93% (3.72%)
8. hardcore - 3.74% (5.26%)
9. Lo-Fi - 3.49% (2.36%)
10. electronic - 3.40% (2.81%)
11. alternative - 3.04% (4.74%)
12. hip hop - 2.47% (2.71%)
13. dubstep - 2.31% (0%)