First, have a spectator freely choose a card from the deck and sign it. The signed card is returned to the deck. Next, show a coin and have both the magician and the spectator sign it on either side. Place the signed coin near the middle of the deck. Because of the thickness of the coin, it's clearly visible that the center of the deck is slightly raised. However, with a bit of magic, the raised area disappears. As you spread the deck, the coin is seen to have visually penetrated into a card. When the card is examined, it's the signed card. Furthermore, remove the coin that has seemingly melted into the card and have the spectator confirm that it is indeed their signed coin. The signed card and signed coin can then be handed out.