You display a stack of business cards with the picture of the Statue of Liberty. Have anyone in your audience sign a card for identification, which is placed face down on the table. When your spectator turns over this card, The Statue of Liberty has disappeared! His signature is on the card proving it is the original signed card!
This is a great idea with the old out to lunch principle. You get a stack of 11 cards with instructions. Use your own rubber band.