Multiple room audio

I was curious if anyone knew of a cheap and easy way to play music through multiple rooms while having the ability to turn off the music in certain rooms. I know there are a lot of expensive high end systems out there but im not really looking to spend that thousands of dollars on this. It would be nice to be able to control the music through a itunes on a computer which would be controlled via iphone but its not necessary. I do have an old 5.1 receiver I could use if needed.

I would be willing to wire the house but obviously wireless is the easier solution and i am not too worried about the aesthetics. I have looked into Sonos a bit but they seem a little pricey.
http://www.sonos.com/default.aspx?rdr=true&LangType=1033

If anyone has any suggestions I would greatly appreciate it.

Thanks

buy a bunch of airport express router/audio extenders. used they are about $65/unit.

squeezebox is similar to Sonos but less expensive and different features.

russound is another company to look into

with apples airplay it is an option

Thanks for the suggestions.
I think my cousin has an airport he doesnt use, Ill have to borrow it and try it out. Seems like an easy option.

The squeezebox does look like a good solution also, I thought it was just for internet radio, didnt know you could play media off of your pc. I checked the russound site out as I had never heard of them, I didnt dig too deep cause they looked like they were more expensive than Sonos.

I have the sonos S5 and while it is pricey, you might want to check out the sound quality and in addition the feature of their mesh technology. The squeezebox relies on good ole 802.11 while the sonos wireless system is proprietary. That is usually a negative but it works in your favor because interference and dropouts are less likely with the sonos system. In addition, the synching of music as you go from room to room is flawless with the sonos when compared to other system (latency etc...)