I saw this video on youtube while looking at Dr. Bunhead video clips. I have no idea why they included the nappy. But, they tend to to weird stuff like that.
diaper science fire oxygen
YouTube - Brainiac - Dr. Bunhead collection 1 <-- it is only for the first clip really. However, the lamp prank sounds interesting, but looks dangerous.
YouTube - Brainiac - Wii <-- Changing the smell and colour of your wee.
I did bump into another random video about how some one claimed on brainiac that used nappies are good source of moisturiser.