Step 1. Get Spotify
Step 2. Sign up for an account at last.fm
Step 3. Enable scrobbling inside the prefs pane in Spotify
Step 4. Check this site to find new artists based on your las.fm recommendations http://lutt.se/lastfm+spotify+new/
Step 5. Enjoy your new found music nirvana
Jason Ball 
Jason, great tip. Spotify is awesome, but it desperately needs an iTunes style Genius or last.fm integration or some other recommendation engine. It is a major hassle for most people to pick the songs they want to listen to, especially from 1+ million songs that are available via Spotify. They should at least get a a basic collaborative filtering engine integrated. I just met with some guys last week who have one of the best collaborative filtering engines out there and they could provide a turn-key solution at a very low cost. If you happen to know the Spotify guys, maybe I can connect them.
Zoli
Good post hope you more post regarding this.. Thanks!