I was interested to learn that it is possible to write extensions (XBox 360 Sensor etc) - I am wondering if it might be possible to interface some kind of control to one of these Quad Copters?

http://www.maplin.co.uk/p/hubsan-x4-mini-quadcopter-with-camera-recording-n64ce

There is no interface unless you can find a suitable remote control that can interface with a computer, even then it would be totally open loop control wise and so I doubt the quadcopter would last long!