When I got married, my high-school magic friend did a trick at the beginning of the bachelor party. He had me pick a card, and sign it, and he returned it to the deck, which was then cased. Then we walked out onto the beach and threw the deck into the Pacific Ocean.
About an hour later a woman came in with a fake pizza delivery and proceeded to remove her clothes. When she got down to her bikini bottom, she pulled out my signed card.
I don't think the trick would have been as good if it had just been a matching torn corner.