I remember hearing about a Xerox research lab that had a whole room where the walls were all whiteboard.

They had a celling mounted camera that would scan the walls. They also had a markup language that the camera OCR software would pick up. So for example if they drew a P in a square, it would print out that wall to the printer. If they wrote an e-mail address in a square it would e-mail a photo of the whiteboard to that e-mail address.

This was 7 or 8 years ago. I wonder if they still use this system.