The synchro one was a fascinating video, Budge. I remember the furore about the millenium bridge - many didn't believe the story about people's steps, they thought the bridge was just wibbly wobbling in the wind.
I imagine everyone here has read Extraordinary Popular Delusions And The Madness Of Crowds. I dip into it every now and again. I like the South Sea Bubble stories, in particular the one about a chap who started a venture called "a company for carrying on an undertaking of great advantage, but nobody to know what it is."