If you pay for Spotify, can you stream wirelessly like you can from itunes to an airport express?
Depends how you want to stream it. I've got a Bluetooth audio receiver connected to my stereo - this one:
and can stream to it from Spotify running on either the PC, iPad or Android phone. Generally just use my phone as then it acts like a remote control too.
Quality seems fine despite the rather long route the music is having to take! Funny to think it's coming down the phone line then over wifi to the phone and then over bluetooth to the stereo! Obviously battery life would be an issue if you're playing for a long time so in that case a PC or laptop would be better.
If you were to stream from a PC you could still use the free edition of Spotify but obviously the adverts would be streamed too!
Anyway - that's the cheap way - I'm sure there are lots of other ways as devices like Sonos or Squeezebox probably support Spotify
Bluetooth, straight from the lappy into some Creative wireless speakers. Works a treat 8)
I use [url= http://www.rogueamoeba.com/airfoil/ ]AirFoil[/url] to stream spotify and various other apps to my Airport Express.