I have a separate solution for that, but it's based on a bunch of music recording gear, which isn't really optimized for quick setup for small demonstrations like this.

Maybe I'll end up buying one of those little attached-cable short shotguns, but I'd prefer to spend my money on a wireless system, or at least something that gives me balanced inputs.

Currently, I have two condensers (MXL 990 and 991-cheap) running into a stereo preamp, which runs two 1/4 line-level cables into a dual 1/4 mono female to stereo 1/8 male adapter I made from adapters and a tupperware, and from there into the HV20's stereo in. Weak points are the unbalanced line-level connection, and the delicate 1/8-in on the camera. The tupperware adapter is actually pretty strong, and, obviously, is user-servicable.

Awesome! gotta love the tupperware :D