glue flicking
My favourite school lesson was woodwork which no-one ever took seriously. Our lessons consisted of cheerfully making that glue (the one you mix in two parts, araldite or something?) and then deftly flicking juicy globs of it onto the back of an unpopular kids neck. The instinctual reaction is of course to try and wipe the blob off. This meant that the unpopular kids in woodwork had to spend the lesson with their hands firmly stuck to the backs of their heads. Our all-time record was getting 11 out of 30 kids thus glued and one of those kids was a double who looked particulary foolish with both hands stuck to the back of his head (as if relaxing) and he spent the rest of the lesson crying and asking other people to dry his eyes for him. What really crowned this fulfilling hobby was the fact that rumours were rife concerning what our woodwork teacher had once been caught doing to a boy bent over a woodwork table and so no-one would approach him and ask for help when they were unable to move their glued hands.
written by Mi*ha*l *ranc*, approved by Log

Jello: a mildly cruel game played in the backseat of a car. It requires at least two people (three is best) and a bench-type seat. When the car turns a corner, the person on the inside of the turn yells "JELLO!" and slams purposefully and violently into the person on the outside. It is not a good idea to initiate a game of Jello if you are the weakest of the participants. Although it can easily turn malicious, Jello is usually a fair game - everyone gets jello'd into at some point. (I suppose in England this would be called "jelly," unless things have changed since I was there last...)
written by Si* B, approved by Log

Also in this range are fountain-pen flicking, and in the chemistry lab, mild acid-filled pipette flicking. Yes, mild acid. We were reckless children, not Bangladeshi honour killers.
written by an*nymou* use*, approved by Log