Check this webside, Pandora
 

I don't know if you guys have heard of http://www.pandora.com/ but it's awesome website that basically customizes your own radio online. I'm always online so this thing was quite refreshing.
It has a wide variety of selections :)

crap....I misspelled Website!

There's already a thread on this.

It's nice but i prefer LastFM.

Pandora doesn't allow anyone outside the U.S.A. to access its radio service, so it is of no use to me.