In 2010, for a project in Abruzzo, Italy, the Futurefarmers art collective built a wooden contraption with a big central wheel. Steered from behind with a shaft similar to the beam of a plow and topped by a bucket- or kitelike appendage made of sticks, the wheel was powered by people walking hamster-like inside it. Trundling around the countryside like a cross between a tractor, a moon rover, and a gargantuan toy, the vehicle—titled This Is Not a Trojan Horse—was a conversation piece, designed to get weather-beaten local farmers, kids, and anyone else who might troop after it to talk,