The Voliro has no such party trick as yet, but it's still a real mind bender. Designed and built in nine months, the prototype is a regular-shaped hexacopter, but each of its six props can tilt a full 360 degrees, allowing a staggering 12 degrees of freedom in the air. That means it can manage a stable hover flying sideways, upside down, diagonally or any other way you care to mention.
Its acrobatic capabilities are more or less unlimited, but the Voliro team (a group of 11 "highly motivated" students from ETH Zurich) is more interested in its ability to hug walls. This could be a huge advantage in infrastructure inspection jobs and the like.
It's hard to imagine how you'd fly something like this manually, although it's fair to say you're never truly flying any quadcopter manually. Flight control software is constantly adjusting the power input to your props, no matter what mode you're flying in.
Even so, would you need an extra thumb to fly something like this? It's hard enough getting your head around orientation flying a regular quad, without having to think about which way's up as well.