Some people may be bored with card tricks, but believe me -- this is not an ordinary card trick!
Your spectator freely selects a card, signs it, and it is placed back into the deck of cards and shuffled. You also select and sign one card, punch a hole in its bottom corner, and tie it with a rubber band. It is then tied to your spectator's hand so the card cannot go anywhere.
Your task is to find the spectator's card in the deck. When you take a random card and look at it, it is not the spectator's chosen card - it's your card with your signature on it. WAIT! If that's your card, then which card is bound in the spectator's hands? Your guess is right -- it's the spectator's card complete with a signature and a hole, bound by the rubber band! A great and magical surprise!
And the end, both cards can be examined and audience can keep their signed and punched card as a souvenir.