Last summer
Me and my friends made a trebuchet in my garden (we have a nice big field that doubles rather well as a target range). That's not really childish, just geeky.

What was childish was sending Dave to clear up the water balloons we'd been throwing while it was armed. To reassure him we stood well away so that there was no way we could set it off.

Well, there would have been no way if we hadn't:
Extended the firing cord
Tied it around someones leg.

A quick jerk of the leg later, and a water balloon arcs its way over to Dave, who was now standing in the dead centre of where the balloons had been falling all day.

Got him right on the arse. He never quite trusted us again after that
( Tedium Alduce me to interlow myself., Thu 17 Sep 2009, 17:48, Reply)