There are several standards for small Mobos. The largest is the microATX standard. The next one smaller is the FlexATX standard, which the Shuttle SV24 uses. The smallest is VIA's new miniITX standard mentioned here (170x170mm). There are also other non-standard designs out there which have a small footprint. Many of the "book" PCs and small business PCs use tiny proprietary mobos. I have an HP e-vectra which is about 8"x8"x3.5" that I use as a server and an MSI "book PC" that I use as a home theater PC. I think the MSI with a Taulatin is the best soloution for this. There are several reviews of this mobo/processor out there. The VIA C3 processor is designed for low power consumption above all. As a result of this goal, VIA had to seriously castrate the FPU unit on it. From what I remember, it's not much better at FPU than about a P2-266 and the integer performance is no better than a P2-400. You would probably have enough power to play DVDs and MP3s, but definitely not enough for DivX which needs about a P3-600 to play smoothly.