The original concept of this trick is credited to Jack Hughes.
A wooden cutout of a bellboy is seen on the magician's table. He has two boxes attached to him: one near his chest and the other at his feet. A spectator freely selects a card from a deck of cards and shows it to everybody but the magician. The card is then returned to the deck and the deck is shuffled.
The deck is then placed in the box at the bellboy's feet. The magician then takes the cards one by one from the bottom box and puts each card in the top box. The magician tells the spectator to tell him when to stop moving the cards. This is done slowly until the spectator calls "stop". The card the magician is holding at the stop is turned around and it is revealed to be the spectator's selected card!
The trick can also be done with the spectator signing the selected card or with multiple cards each signed by their respective recipient.