The Squirrel Catapult

I just saw this video linked from Casa BoingBoing yesterday: the Squirrel Catapult! This is just awful! What appalling cruelty to poor harmless.... Oh, who am I kidding? I hate those evil, destructive little bastards, and I want a squirrel catapult of my own, like yesterday! Now all I need to do is find a way to have it trigger and reset itself automatically. And maybe if I aim it at a nearby tree...