A true classic of magic, with origins dating back centuries.
A small plastic ball is removed from a blue plastic vase, and placed into the magician's pocket. The lid is then placed on the vase.
With a magical gesture, the ball is seen to have re-appeared back in the vase. It is then seen to dissapear, and appear back in the magician's pocket.
This is a very easy to do magic trick, that comes complete with instructions.