The wallet and keys seem like vulnerable species on the contiuum of conservation statuses: A lot of things, like the smartphone, are actively trying to kill them. They're not quite endangered, though, because nothing's good enough yet to make them imminently extinct — payment apps aren't taken everywhere, they can be clunky, they don't always work. But you can also see how one day, inevitably, the billfold is going to die — or at least become something only hipsters carry.
This AT&T project, "Bio-acoustic Data Transfer" or "Key Transmission Through Bone Conduction" is one way to replace jangly, pocket-cramming, body-part-stabbing keys — using your body as a medium to transmit data. In this case, a piezo-electric transducer is attached to a smartphone (or watch or whatever), and when you touch the door, a unique digital key is transmitted from your phone through your body to the door, releasing the lock. And because everybody's skeletal structure and bone density is unique, the key only works for you — it can't be stolen and used by somebody else to break into your house and eat all your cereal.
The same principle, using your body to transmit data, has other applications, like one AT&T was touting, handshake data transfers. So instead of swapping business cards or using a "bump" app on your phone, skin-to-skin contact would seamlessly transmit contact info — and GERMS — to your phone through your body. Or any other kind of data, really, (GERMS) though the researcher working on the project, Brian Amento, says that they don't have the equipment yet to really measure how much bandwidth your body has to offer for data transmissions, so they've mostly been testing small images and the like.
This is a ways off from being commercially available or mainstream (it certainly won't be a pile of exposed guts like in the picture), but, like Pay With Square, technology like this is precisely why things like QR codes and "bump" interfaces for payments or exchanging data feel like the niche technological kludges they are: These kinds of transactions will be invisible. You won't need to pull out anything — a card, a wallet, a key or a phone. You won't need to precisely line up your phone's camera with a tiny garbled square or tap something to something else. You'll say your name or touch an object — with your hand — and things will happen. And that's when our wallets and keys will be history.