They're not going to turn you into a Doctor Octopus-like super villain, but the next time you're trying to open a door with your arms full, you'll wish you had an extra set of shoulder-worn robot arms being developed at MIT.
Just don't get your hopes up about flipping away speeding cars that are about to hit you, or yanking the doors off safes. To keep them around five kilos and fairly lightweight, your arms are probably stronger than these artificial ones. But sitting high on your shoulders they can easily outreach your own limbs, and are designed for tasks where two arms just aren't enough.
What makes these robot arms truly impressive is that they're actually able to study and learn the way your body moves, and then make predictions on how you'd want them to help. In the video the arms are simply mimicking the movements of the wearer's real arms, but eventually they'll have a (limited) mind of their own to come to your aid as needed.
If your arms are full of grocery bags, you can't exactly go through the motions of opening your front door to demonstrate how it's done. But after repeated grocery trips—and probably a few dropped bags—the arms will ideally eventually learn the pattern, and then automatically reach for the doorknob as you approach your home.
The same goes for other situations where these arms could prove to be invaluable. If you needed to screw a panel to the ceiling above you while holding it at the same time, the arms could eventually be taught this routine so that after you've held the panel up, they'll autonomously take over, ensuring it doesn't fall as you're working the drill.
This approach is certainly not as impressive as a full-body exoskeleton, which can considerably enhance a wearer's strength and capabilities. But at the same time, it's also far more feasible with the technology we have today. Would you rather wait 20 years for a bionic super suit, or just five for an awesome set of extra arms? [MIT d'Arbeloff Laboratory via IEEE Spectrum]