It's been quiet on the thread a bit. I just put in an order for a collective-pitch heli, and I expect it'll take some time for me to learn it (since I've not flown a CP before).
I was wondering if there's more room to minimize the size and weight here. Either by making a "stickduino shield" or just going straight for an Atmel on a heli-oriented board. And adding an air-pressure altimeter seems like a no-brainer, except helis are low-altitude and I'm not sure how accurate the devices are when near the ground.
It seems like the ultimate aim is to let a program dictate higher-level commands to the heli, like "lift off gently," "climb to 30 meters," "turn to heading 270," and maybe even patterns like "zoom forward and tilt up into a stall-left turn." While flying manually is a great amusement for some, I can see this as being more task-oriented for serious applications, UAV style.
Adding a couple generic "accessory activation" pins would be interesting as well. Nerf launchers, cargo winch drivers, cargo jettison, camera triggers, laser or light effects, ...