I saw an effect where the magician had the spectator put their keys or credit card in one of the small lockboxs. A magician then told the spectator to mix the combination and as they are doing this the comedy as he said but be sure remember the original combination. They do not of course remember it. He then use his deck of cards and for Random(?) Cards are generated by the spectator and they are the combination to the little lockbox. The rest of the deck is shown to be blank face cards.
I can't remember where I saw this if someone has the information I would much appreciate it