It's a fantastic toy. It has an Arduino based auto pilot on which is actually doing all the hard work of controlling flight as apparently a quad is inherently unstable and would not fly. Even in a hover you can hear the different motors changing pitch to keep things in check.
Rob - I did non of the hard work. All the PID are pretty default except a few which I tweaked which seemed to make it a bit more stable (differences in frames and etc)
More info here:
http://code.google.com/p/arducopter/wiki/ArduCopter
The whole auto pilot thing allows you to set way points, upload it from the laptop and it'll fly there by itself. All pretty awesome. The idea was originally for Tony and I to be able to exchange a beer. He lives about 600m LoS from me so pretty simple
Here is the auto pilot and telemetry setup (real time updating)
Wobbly - that was supposed to be my MC HQ (Man Cave HQ) but my wife invaded and filled it with stuff from her business. I was kicked out
Bob, there is a front to it normally. It can either fly X mode (as I have it) or + mode. it also has a mode where there is no front and you fly the compass. You push forward and it goes north. Pull back and it goes south. The computer does all the hard work. You can also set it into a spin (like a spinning top) and still fly fowards and backwards. Again, autopilot does all the work.
The props are opposed along an axis so to turn left, it slows one side, speeds up the other side as well as the opposite to maintain lift and the torque difference causes it to yaw.
Here is Tony flying his today:
[youtube:38eo6lgo]Lyq4_fPvZRM[/youtube:38eo6lgo]
Gav - it will be at Lincomb and if the new bits are out, I will have them to. You get to mount a device to something like a car. This then talks back to the quad and quad follows it from a pre-determined distance and hight. I was thinking of the challenges in the field. Clip one onto the truck and the quad follows from above and behind filming it. How very cool

Due out in Feb / March.
Tony got some cool footage from today with an onboard camera. Paging Tony.