That's Not A Knife, This Is A Knife!! Credit Card With Big Blade
I've seen credit card-style multi-tools like the Victorinox Swisscard around for years. A lot thinner and sleeker than your average multi-tool, card-based tools slip a number of handy gadgets into a card-like profile. They're typically limited in the knife department, however, including only a small blade, if anything.
The Iain Sinclair CardSharp Credit Card Folding Safety Knife, on the other hand, uses a different strategy. It eliminates all those other tools like scissors, tweezers and screwdrivers and focuses on a legit folding knife. The CardSharp features a 3-inch, folding blade that looks like it could shave a piece of paper in half--depth- wise.
Instead of just pulling the tool out from the card, as you would with other card tools, you tranform this card into a knife with a series of three folds. When unraveled into card shape, the card serves as its own sheath, protecting you from accidental pokes. And there's no more, belt-mounted sheath; just pack this 13-gram knife into your wallet and you're ready to go.
It's a little bit scary, as you could imagine this being used by muggers or criminals, but a pretty innovative take on the "pocket" knife. The CardSharps are expected to be ready for shipment in the first quarter of next year. Price is set at 15 pounds (around $23) and you can preorder now. (Update: The credit card knife is now available on Amazon here.)
If you're looking for something similar but a little sooner, the Tool Logic CC1SB includes a 2-inch serrated knife and a few other tools for about the same price.