i remember a short-lived period at our high school where there was a craze for putting thumb-tacks on peoples seats when they weren't looking then waiting for them to sit down for the inevitable sore arse and much hilarity

there was also something that went round with people popping the metal tops from bottles of oasis in folks ears to make their eardrum pop, most painful and pretty bizarre

all pretty tame but i imagine if some bed-wetting parent got wind of it the first one would at least make page 5 of the metro these days