I'll put out another solution. This requires that you have powered speakers, like AudioBytes or Audio Engines. If you have those at different locations, you can use Apple's Airport Express and send music wireless using Airtunes. Play your iTunes around the house and control it w/ a PC, Mac, iPad, iPhone or iPod Touch. You can even control volume. If you pair that w/ Airfoil, then you can add stuff like Pandora. This is a poor man's Sonos solution.
OR, you could use a wireless speaker that they have at Brookstone. It's mono and 900 MHz, IIRC, but it's portable and sounds surprisingly good.
