I've been interested in 3D printing ever since I heard of the idea. The Rep-Rap is an interesting project. They're making a 3D printer which will be capable of printing the parts it's made of. It needs a fair bit of control, and I'd like to do this control from inside Linux.
Turns out that there's a perfect system for doing this, called the "Hammer". It's put out by Tin Can Tools. They put an ARM processor, with some ram and flash on a 40 pin carrier. All it needs is +5V and whatever hardware you want to connect it to. I will, of course, be connecting it to three quad half H-bridge drivers, to run the stepping motors.
No, I haven't made any progress on it yet. Too many projects in my life! But I've got the module and their demo board, the H bridges, and just need to get my butt in gear.