i stumbled across this link which calculates how long you've spent listening to the artists in your last.fm charts. And personally, i think this is a much more accurate depiction of your true tastes (though its a slight estimeate i think)

http://www.associativetrails.com/stuff/normalisefm/index.cfm

So, anyone had any massive changes? Mine was fairly similiar, although Faust, Miles Davis and The Grateful Dead all jumped about 16 places, and the Minutemen dropped 38 spots. Serves them right for cheating all this time