Does anyone here have a Last.fm account?
No, but they do link to my youtube video.
What's the benefit of joining?
It's just like Pandora radio, only I find it to be significantly less restrictive. You don't have a limit (that I notice) to how many times you can skip a song. I find that for my musical genre of choice, they have a LOT more songs with a lot less repeated songs (on Pandora the same songs would play, but on Last.fm, it uses the entire album).
Signing up "scrobbles" everything you listen to and puts it on a chart so people can see what your musical tastes are...kind of cool to pass around with other people of similar tastes to compare and whatnot.
I started using Last.fm and never looked back at Pandora again...