Flutterby™! : Drone Helicopter Hybrid

Whoah, super cool: Shadow forwarded along Drone Helicopter Hybrid (YouTube video). With the right hinged head design, you can build a helicopter main rotor that's controlled by the acceleration of a brushless motor. No swashplate. The built helicopter uses a tail rotor, but you could probably also do this with contra-rotating main rotors... At any rate, two motors, no other active drives...