If you can put up with ads, you can easily trick Spotify and sign up for an account, even if you're not in one of the supported countries. You'll need:
- A Facebook account
- SSH access to a server based in one of the supported countries (US, UK, whatevs).
First, set up an SSH tunnel, as described here: http://paulstamatiou.com/how-to-surf-securely-with-ssh-tunnel
Once you're done, go to http://whatismyipaddress.com/ and make sure the map shows you the country where the server is located.
Now you should be able to sign up for Spotify. Download the app, log in and voila. You can now turn off the ssh tunnel and the app should work fine.
There's a small catch, though. Spotify lets you "take your music abroad" only for 14 days, but there's a way around. When your trial expires, set up an SSH tunnel, then go to Spotify -> Preferences -> Proxy. Select "Socks5", enter host and port. Restart the app and your trial should be re-set. After that you can turn off the proxy settings and close the tunnel.
If Spotify shows you only the login window and you can't get to the preferences, do the following: turn off your airport, try to log in to Spotify. It should display an error message and allow you to enter the proxy settings.