The Moody Bill illusion

I had originally discovered this trick while reading Origami to Astonish and Amuse by Jeremy Shafer. Creating the illusion is very simple. You fold the portrait on a bill a certain way, a valley fold bisecting the mouth with two mountain folds on either side. The result, depending if you look from the top on down or the down to top is a frowning or smiling president. Yes, it's very, very silly. But, trust me, after you've done it once, you will using it as your go to stupid party trick. Personally, I like using five dollar bills for the trick. There's something about Lincoln that is always ripe for comedy. Link goes to Metacafe.com video instructions.