Find The Coin

Effect: A coin is covered with any one of three cups and the cups  are then moved around. You can say immediately which cup is covering the coin. Secret: Attached to the coin is a long hair. When the coin  has been covered the three cups can be moved around as much  as anyone wants.  Although your back has been turned while this has been going  on you can easily locate which cup hides the coin.  All you have to do is look for the hair sticking out from beneath one

of the cups and that tells you all you need to know!