The Human Computer by Alex McLittle

You say to your audience that you are a human computer, and that all the information you receive is saved on a disk. You then take out from your pocket a computer disk, on which there is a label with the word “thought” written. This disk, which you’ve dubbed your “drive”, is signed, and then placed in your pocket.

The spectator “freely” chooses five cards from the deck, and from those five cards, freely memorizes one.

After some humorous asides, you take out the disk, showing that it is still signed by the spectator. When you slide open the disk, the spectator will be amazed to see that their card is INSIDE the disk!