Layers and layers of Sudoku games in a bar of soap.
Wash up a bit to expose the game, and then play by scratching the numbers onto the bar.
Keep washing to get to the next game.-- zigness, Dec 12 2005 An excuse to get clean, I guess. +-- DesertFox, Apr 17 2006 I don't think it would unlayer evenly, but maybe the tiles on your bathroom wall could be made into a sudoku grid instead?-- phundug, Apr 17 2006 I think you could get it to unlayer evenly... maybe alternate dense and softer layers when making it.
The bathroom tiles... hmmm... that's a thought.-- zigness, Apr 18 2006 random, halfbakery