I was wondering whether anyone knew of a way to stream music throughout a house on a budget?

I want to avoid spending any money on this (eg. I don't want to buy a d-link style device). It would be ideal if I could use my existing hardware and some open source software.

I have three old(ish) PCs knocking around. I'm happy to stick either Windows or Linux on them. They can all be hooked up to speakers.

The ideal solution would result in:

• the same audio being heard from every device (eg. when you hear a beat on one device, you'd hear it at the exact same time on another (so you don't get any echo))
• I'd be able to control the source application (eg. the songs lined up) with my iPhone.

I realise I'm being cheeky with those two wishes - but you never know your luck.

Am I asking for too much, or is there a piece of software/protocol out there with this purpose in mind? I've been searching for sometime now, but haven't had any joy.

Thanks in advance.