Rear wheel steering does allow for very tight turns, but it is rather dangerous at high speeds. There's a tendency for the car to fish-tail out of control. I know some cars have been offered with all-wheel steering. Usually, they are computer controlled such that, at low speeds, the front and rear wheels turn in opposite directions, but at higher speeds they turn the same direction. This provide tight cornering at low speeds for parking and safer high-speed lane changing. The rear wheels always turn at less angle than the front to keep it from acting too squirrelly.

Sand is right, rear wheel steering is more maneuverable, hence it's use on lift trucks. But when the front wheels steer, the change in momentum for a turn happens earlier, and I think before the center of gravity, so it's just more stable.

Buckminster Fuller's 'Dymaxion car' was a rear-wheel steered vehicle. It's always been one of my favorites, but likely that's what caused it's failure. http://www.washedashore.com/projects/dymax/