Modern Marvels: They stun, debilitate, immobilize--providing police and peacekeepers with options other than shouting or shooting. From the ancient caltrop--a multi-pointed contraption hurled by foot soldiers into a horseman's path--to sting-ball grenades, electrical shock devices, and sound, light, and energy weapons, we examine non-lethal weapons that disperse crowds and take down criminals. And in a whiff of the future, we see why the government thinks stink bombs might prove useful in the war against terror.