This Autopilot for Aerial Photography slide show that was done for Barcamp Antwerp looks really interesting.
“The autopilot has a built in mixer. On first use you need to tell the autopilot what the channel and mixer arrangement of your transmitter/airplane combination is. To put the autopilot in calibration mode, switch on the transmitter, put all sticks in the center and switch channel 6 to “ON”. Now turn on the airplane.
At this point you can calibrate the autopilot by putting all sticks in the center and subsequently actuating the aileron stick from full left to full right and back to center, followed by elevator (fullup, then down, then center), rudder (left, right, center) and throttle (zero throttle, max throttle, center). The autopilot will confirm completion of the procedure by turning the rudder full left, then full right and then back to center.”