After Pandora got taken away from the UK; I found Spotify, and that is what I am using currently.
I have the free version, but that is currently shut off, because of high demand.
It may come back at some point, but otherwise, its £9.99 a month. But for that, you can listen anywhere, on an ipod/iphone, etc, and have 320kbps OGG playback, compared to the 160kbps you get with the free version, plus any other exclusives they have.