AlienVisitor wrote:
I've got a question. Why do people use their hands when talking?

Ex:
http://www.ehow.com/video_4401601_impro ... eech_.html
As a kid, I wondered about that too. When my dad talked to me eagerly because he wanted to make me understand something, he would use gestures with his arms / hands, and I asked him why he did it. As I viewed it, it was totally unnecessary, because I could hear what he said and understand it. He would answer that he gesticulated.
Today I myself may gesticulate. But maybe in a different way from the NT way (a psychologist has told me). But I can't see it myself. And noone scolds me for that reason. So it doesn't matter.