Piccolo is a neat little plotter/drawing robot that's open hardware: http://www.piccolo.cc/ http://www.piccolo.cc/ Unfortunately it seems nobody offers a full

Piccolo is a neat little plotter/drawing robot that's open hardware: http://www.piccolo.cc/ http://www.piccolo.cc/ Unfortunately it seems nobody offers a full kit, so you'll have to gather materials yourself. It looks like it'll take four or five orders... ponoko for the laser cut parts, seeed studio for the pcb, hobby king for motors, and so on. Also not sure it fulfills the "build on top of that" requirement either, though after it is built you could spend lots of time learning programming to make it draw cool things. Think LOGO with an actual pen!