Can you tell that I listen to my iPod on random? http://www.last.fm/user/ianzabel/charts/?charttype=weekly&subtype=artist

how is that information captured?

A little plugin that uploads everything you listen to. http://www.last.fm/download/

iiiinteresting. would be useful to track what I listen to. I want to delete a bunch of stuff from my iPod.

If you want to track your iPod, you have to install the iSproggler one. Then, every time you sync up, it'll upload what you've listened to.