The Make blog notes this portable wooden CNC machine made by Nick Santillan. Nick wanted to experiment with CNC technology without the expense of outsourcing the jobs. He researched building his own and ordered some DIY plans, but, after nearly completing it, decided it was not up to his expectations. After more research and the purchase of better bearings, slides, and so on, he designed and built the wood-framed CNC machine shown above.
Nick’s machine has three main parts (shown below) that allow quick assembly and disassembly, easy transport, and storage in a smaller space. His design has a moving gantry with an open table so the CNC can directly engrave or mill the surface if desired (i.e., by bolting the CNC to a table or wall, you could mill that table or wall). The removable tool holder, which currently holds a plunge router, can be customized for almost any tool — lasers, anybody?
3-Axis CNC Machine [Manufacturer's Site]