Don't forget the XH-A1. The manual for it is here.
http://www.usa.canon.com/consumer/co...&modelid=14061.
This camera is based on the DIGIC DV II like the HVs and has the same OSD and menus. Jolly mentioned something about junk code in the firmware... maybe the code for some of the extra menus like manual gain/noise reduction are laying dormant in the HV firmware and can be switched on. More than likely the firmwares are stripped back with useless code ripped out but it's conceivable that there is one base firmware for all DIGIC DV II cams with a bunch of flags describing the specific device. Afterall this turned out to be true for the region setting and my guess is the HV20/30/40 all have %99 identical firmwares.
Hacking the menus and coding new routines from scratch sure sounds like fun but it would be real handy if we could just use canon's.