At first glance, it may look like a credit card, but it’s actually a functional solar-powered calculator — priced at $6. Best of all, it fits nicely in your wallet. Click here for one more picture.
I could carry it around in my wallet and work out a tip or a grocery bill as I go. It’s also a decidedly nice design, looking enough like a credit card that maybe it’d appeal to the spy in all of us, as well.