I could go and pick up on all the minute statements which make up the whole of this interesting thread and detail my thoughts on them- but that would take too long. So, I'm simply going to say that I found the video and opinions in this thread highly amusing.
I'd never particularly paid much attention to my hand movements when explaining something, but my friends have repeatedly made comment about it. When I debate with someone, the hand motions are most readily seen, but when speaking with friends and explaining a concept which I feel one may not be readily acquainted with, I apparently do close my eyes (most likely to focus) and gesticulate concepts in a manner many may understand (physically). An interesting point, nonetheless.