Well, I was testing the performance of the camera and different screen materials/colors.
A cyc of light green paperboard seemed to work best (the phone/Zen at the beginning).
I know, these were some pretty crappy keys, but I didn't try very hard. Knowing how little I really tried to customize the key, and how I still need to play around with keylight, I was impressed with the HV20's performance (or, with the keyability of HD in general).
Oh, and I really hate the way my shirt goes up on my back at the end. I need to run more.