Awesome, this is one of my favorite XKCDs. I've been mulling over a plan in my mind to make a physical version of it, looking similar to a deep picture frame or display case. It would use white acrylic with the text somehow printed or transferred on, backlit by white LEDs (maybe incandescent lamps would look nicer?). Each cell would be separated by thin black wood or plastic strips. It should be pretty easy to control the whole thing with an arduino, and I think it would make an awesome wall display.