This is fantastically cool. Similar to the e-ink cards that were posted here recently, a really neat application would be pre-programmed pen-and-paper board games that people distribute to each other, and you can then play with someone remotely; their edits to the board would show up on your device and vice-versa. Think hangman, battleships, etc. You could probably even do checkers/chess, by drawing an X over the piece you want to move & then drawing it at its new location, or something, though I don't know that this kind of interface would be better than a normal GUI. For the whimsy, perhaps.