Meet the Omnicopter: a flying machine with 6 degrees-of-freedom that can generate forces and torques in any direction, allowing it to fly at arbitrary altitudes. The Omnicopter is a 45cm cube activated by 8 brushless motors. Its propellers can produce positive and negative thrust.
The Omnicopter has control over all its 6 degrees of freedom. It can rotate by hovering on the spot and perform novel maneuvers. More info is available here.