Digitally splicing a sliced-up [http://www.metmuseum.org/Works_of_Art/viewOne.asp?dep=7&viewmode=0&item=37.80.6|tapestry] can be really tricky even if you're a world-class nerd with two bodies. "The lights were dim. The walls are concrete and painted white. The brothers project images on the walls, and they also use the walls as a whiteboard to perform calculations with erasable markers. The walls were covered with scribbles -- work in progress. Most of the floor consisted of a vast digital image, in color, showing a hundred and fifteen different equations arranged in a vast spiral that breaks up into waves near the walls -- a whirlpool of mathematics." [http://www.writing.upenn.edu/~afilreis/50s/zinn-chap16.html#comm-control-act|Greenglass and Rosenberg, so it is said], used nothing more than a ripped Jell-O™ box top as a token. It's neat how easily verifiable yet difficult to reproduce (or nondestructively manipulate) a small broken object can be. Via [http://www.massey.ac.nz/~rmclachl/|Robert].