Mental detector

Mentalists attention, this is a wonderful effect!

The magician (mentalist) has a ball for him and a group of spectators. The ball can possibly be investigated. He gives the ball to a spectator and the magician turns around.
The viewer gives it to another spectator or keep it himself, what he wants. Possibly there are even more "shaken".
Spectators stand in a row with their hands raised. One person in one of his hands to the ball.

The mentalist is impossible to know who and in which hand has the ball. He concentrates and then assign the hand to where the ball is!

Beautiful.
Can also with many other objects. Once you know how the gimmick works, you can do this with many objects.