Today, this page is just a place to collect links + references usefull to creating video recordings of what happens on the screen of a demo. If we get it together this page will become the How To for the best + simplest methods.
Back last winter there was some discussion about making recordings of talks + demos, like the Hants LUG regularly do.
OSS Software to record screen activity http://camstudio.org/ sorry, this is windows only.
Camtasia from Techsmith - similar commercially available software.