X ray box
A spectator draws what appears to be a playing card at random and places it in his or her hand. The magician takes out a small box, which he advertises as an X-ray machine. an empty, transparent film is put in, the can then closed with the deck.
The whole thing only has to be held briefly over the spectator's hand and the x-ray in the can seems to have developed - the spectator's hand appears on the foil with a card lying on it - of course it's the drawn one!
An incredibly amazing feat that will delight young and old alike!