EFFECT: Two coins and a clear balloon are placed on the table. The magician inflates the balloon while the spectator selects a coin. The balloon is sealed off and the magician now takes a coin and visibly pushes it into the balloon! If that's not enough, the magician now plucks the coin back through the wall of the balloon and shows the coin free again! Instantly the coin is popped back inside and the balloon can even be given to the spectator to keep!
The coin is really trapped inside and creates an amazing and memorable souvenir.