“America is the only country in the world to have gone from barbarism to decadence without going through a period of civilisation in between.”

Unfair but apt. How times have changed though. I worked for Unisys back in the late 80′s and went on a presentation skills course run by one of the Americans. She told us it was bad form to change an OHP slide while it was being projected so we were all presented with a polished piece of aluminium (complete with compay logo) that was designed to be hung from the mirror/lens part of the OHP and that you flipped up and down to hide the image while you changed slides.

Mind you, the upside of low tech presentations is that because of the work involved in making them, they tend to be much more concise and to the point.