One of the most popular pocket tricks of all time. A coin is borrowed, and vanishes from the magician's fingertips. A small box is removed from the magician's pocket. 

This is handed to the spectator, who opens the box. Inside he finds a matchbox, encircled with rubberbands. Inside the matchbox, the spectator finds a small bag, also closed with a rubber band. Inside the bag is the missing coin!