Preparation:
You need a pen and a deck of cards
Method:
Have the spectator select a card from the deck and show it to the audience.
After the card is signed, control it to the top of the deck by means of a Hindu Shuffle control or a revolving pass.
The deck is now held in the standard dealing position in the left hand (with the chosen card at the top)
Get a finger break under the top card and palm it with your right hand immediately.
Flourish the rest of the deck with a one hand cut, or one hand shuffle with your left hand and offer it to a spectator to simply mix up the cards.
Make sure the spectator starts to shuffle because some stubborn people start to shuffle through the deck looking for their card.
Then turn your back making this move seem natural to show at there is no possible way that you could know where the card is .
At this time you are folding the palmed card into eighths (The smaller the better) This is easy as your back is turned you can use both hands to do this and then slip the tiny package in your mouth between your cheek and gum.
Turn around to face the audience as the card is folded so tightly in your mouth, you can talk normally.
Take the cards and act as if you messed up.
Turn over a couple of cards to reveal what was supposed to be their selection.
Do whatever you want , just make yourself look, bad .
As soon as people start to laugh at you , act as if your hurt , as if something inside of you is wanting to get out.
Make the audience curious , and have the suspense build up.
As soon as they reach their peak , work the card out of your lips and and slowly spit the card out onto the palm of your hand.
Unfold it , and watch the audience scream at the chosen signed card. It looks as if you somehow swallowed the card beforehand and regurgitated it back up again.