You should also check out a DVD by Helder Guimareas called "Small Miracles." In it there's a routine where a spectator freely selects a card. A few blank cards are introduced. The magician then prints the selection on all of the blank cards. To finish, he shows that the spectator selected the only printed card in the deck.
John Guastaferro has an effect on his Second Storm DVDs that is also worth looking into. The magician introduces a card with the word 'prediction' written on the back. The spectator chooses a card by rolling a couple of dice. The card is revealed to match the prediction. The magician then talks about how the trick never happened. The prediction card is revealed to have changed to a blank card. The selection is also blank. The dice are now blank as well with no spots. Finally, the deck is spread and revealed to all be blank. It's very easy to do and would make a great closer.