Multi-Room Wireless Sound System?

abrinton asks: "I just went into escrow on a new house. Of course, first thoughts are to the sound system. I don't want to wire. Anything. I've got a wireless network, so computers are all sorted. But what do I do for sound? I need ideas for a centrally controlled sound system that can use 802.11g for transport. I'd like to have the same music everywhere, or better still, options to play different things in different rooms. I've got access to tons of old PIII laptops, wireless gear, old computers, sound cards, etc to make this work. Has anyone got any ideas or done anything like this?"