OH, I got one - maybe you could have a card selected...then shuffle cards face up into face down...and then when you spread them - nothing happens. The deck is just a mess...I bet it would fool magicians.
How about this one - you pretend to take someone's nose, like when they were a kid...and put it into your hand...then it turns into a car....you open the car door and a beautiful women comes out...then another...and another...eventually every Playboy Playmate comes out of the car from the past 50 years...then Hef comes out with his three ladies...everyone that came out of the car has a deck of cards....Hef picks one card and signs it...then ALL the decks are combined...you then produced Shaquille O'Neal from behind someone's ear...he is required because he is the only one with hands big enough to shuffle up all the cards....after the cards are shuffle...you get Shaq to throw the cards at a window....the window breaks...and sign is behind the window....and it says, "THIS IS THE MOST STUPID THREAD IN THE HISTORY OF T11" - Everyone freaks out and applaudes...because they agree.