This piece of guerilla art was originally put up as a joke — Pasadena, Calif. resident Bob Stane made a lot of corny jokes about putting a fork in the road at this fork in the road, so his friend made him an 18-foot-tall one for his 75th birthday. It wasn't technically legal (the fork's creator, Ken Marshall, said his police officer son told him "Dad, you're going to jail for this"), and eventually the California Transportation Authority had it taken down. But by then the fork had become so popular that the city of Pasadena negotiated with CalTrans to allow the fork to go back up. Now fully permitted and above-board, the fork has been cemented into place by its staunchest advocates, known as the Fork in the Road Gang.