You might see about getting a copy of CNC Robotics by Geoff Williams (ISBN 0-07-141828-8). It's a real interesting book which shows how to make a CNC router table. The author made his 4x7 feet and shows how to use it with various cutting/engraving tools working in various materials. It looks like it's reasonably easy to build a machine that will do some pretty cool stuff. I've been thinking about building one myself, since I have a few salvaged machine parts lying around. My table would be smaller than his though (20x20in working area or so)...
Jeff