At first I laughed and felt less like a delinquent when I read these posts. It's amazing how similar others' interests were.
I did the hairspray flame-thrower (and even progressed to a can of starting ether). I made gunpowder, schrapnel grenades, perfected a remote igniter using a drycell and light-gage steel wool. Drilled holes in planks, inserted shotgun shells, and used a BB gun to hit firing pins. Hitched a sledride on a postal jeep bumper. Received many shocks from experiments with alternating current. Was run over by a horse, a tobaggan full of people, and had several body-as-projectile incidents over the years. How did I avoid serious injury or death?
On the other hand, this thread makes me much more worried about my own kids, because now I realize it wasn't just me and my sick pranks!