Cut a strip of tape 8" long and place it, sticky side up, on your desk.
Cut another strip and place it, sticky side down, on top of the first strip.
Flip this over, and place another strip underneath the first strip, on top of the second strip.
Flip this back over and add another two strips of tape to the top and bottom.
Continue this until you have the length you want your wallet to be, about 3". At this point, trim off the excess sticky tape at the top edge of the wallet.
Continue down until you have double the height, 6" long. Trim off the excess sticky tape at the bottom.
Fold the wallet in half, length ways, so that the wrong side of the wallet is facing out. Apply a strip of tape to either side, to close up the open edges.
Fold this inside out, so that the right side is facing out.
Using a similar process, create a recentangle the matches the width, but is a little shorter than your wallet.
Stick this to the bottom of your wallet to create a card pouch.
Make another little rectangle, shorter than the last and half the width.
Stick this to the left hand side of your wallet.
Your wallet is now ready to store your money and cards.