"GeeXBoX, a small media center Linux live CD distribution, can run from any small device, such as a USB disk or a wallet CD-R, and can play both disk-based media like DVDs and online media like Icecast streams. The project has been in development for several years and has just released version 1.1. I fed it every kind of media file I could lay my hands on -- Ogg, MP3, MP4, AVI, DVDs, VCDs, and their ripped versions -- and it played them all without a hiccup. But what makes GeeXBoX a fantastic distribution is its ease of use and malleability.
"GeeXBoX 1.1 is a mere 8.9MB ISO download. Its hardware requirements are minimal -- a Pentium II 400MHz processor and 64MB of RAM are enough to power GeeXBoX--and of course you'll need a CD/DVD drive to play your media..."