COIN TRANSFORMATION.
The Magician shows a coin in each hand. He rubs the two coins above the spectator's hands and a much smaller coin (Quarter Dollar, 50, 20, 10 Euro Cent) falls into the spectator's hand.
At the same time one of the larger coins disappears. The Magician spins the last coin in the air so it can be seen by all.
The appearing coin can be handed out as a souvenir.