There's a reason that birds perch: flying is a lot of work, and until we teach our drones to survive off of hopes and dreams, we're (nearly, and nearly again) always going to have to deal with severe restrictions on flight time, especially when hovering. Drones have been working on perching for years as a method to extend their usefulness for stationary surveillance, and this modified AR Drone takes inspiration from falcons with some custom legs, claws, and feet.
We don't get a lot of visual detail beyond this (admittedly kind of terrible) video, but according to New Scientist, Vishwa Robotics, in Brighton, Mass., designed these perching legs with actuated feet equipped with sharp little claws. The drone approaches a landing point, performs a controlled stall, and actuators cause the feet to grip as the drone shuts down its motors. Once the perch is complete, the drone can sit there without expending any energy at all.
What this video doesn't show is that the drone can apparently "waddle short distances, so the drone can explore indoor spaces." And the AR Drone use case is just a proof of concept, and eventually, these legs are intended to be added to a variety of small drones.