You've seen one quadrocopter juggle a ball autonomously while gliding through the air, but how's about a pair of them working cooperatively? Yeah, we've got your attention now. The Zurich-based lab that brought us the piano-playing and ball-bouncing quadrocopter is back with a simply breathtaking display of robotic dexterity and teamwork. Like all mad scientists, they call their Flying Machine Arena research "an experiment," though we see it a lot more as a Pong-inspired dance of our future overlords. We all know how far video games have come since two paddles batted a ball between one another, right?