Talking of presentations, we were reminded recently by psychologist Tommy MacKay that they contain hidden dangers. At an appearance before 300 delegates in Paisley, he stepped behind a screen to lay down his briefcase. Alas, he had not appreciated there was a 4ft drop into the darkness.
There was a loud crash, a few groans and "the passage of a rather longer time than one would normally take to lay down a briefcase".
MacKay emerged from the depths, unbloodied and unbowed but with a finer appreciation of platform perils and no lasting psychological damage - we think.