Spotify has opened signups for UK residents, but if are not then using following steps anyone can signup
1) goto http://defilter.co.uk/ or http://2proxy.info/
2) Enter the address http://www.spotify.com/
3) Click on Get Started
EDIT: Mods, I apologize, I didn't see the notice regarding Spotify signups to be posted in the music section, so Please if can move the post that would be great.