Whenever [sprite_tm] sends in his latest project, it's like getting a Christmas present and a night off. He put together a whiteboard, x/y stepper system, serial interfaced microcontroller and added a webcam with perspective correction for the online view. Me? I'm tempted to build one of these for leaving notes for the wife when I'm out.
http://www.hackaday.com/2008/04/28/remote-control-whiteboard/