A spectator selects a playing card and signs it. Then you loose the card in the deck. Turn the first card over and show it back and front. Now you hit the deck with this card and instantly and highly visual the spectator's chosen card appears on top of the deck! The spectator can freely examine his card and it is indeed the original one!
Hith the back of the deck with a playing card, a credit card or a telephone card.
Back on the top of the deck in 1 second!