Tuning the OpenPilot CC3D for gimbal control.
Update April 2014: Sorry I never got around to updating this video, I switched to a brushless motor gimbal and with an Alexmos controller quite awhile ago. The CC3D when tuned right is very capable of controlling a gimbal but as far as I know it will only work with servos, and unfortunately that style of gimbal is not nearly as good as brushless (if you haven't tried it yet what are you waiting for?!).
Update Jan 2013: I no longer think the "Zero gyros when arming" option is the cause of the bias, so you can ignore that part of the video. The rest of the info is still accurate so this will still assist you in tuning your CC / CC3D and gimbal.
Gimbal info:
http://www.rcgroups.com/forums/showthread.php?t=1739869