The pilot had planned to depart on a local solo flight. He completed a preflight inspection of the airplane, which was parked outside of the pilot's hangar and pointed towards a set of hangars about 50 feet away. The pilot then primed the cylinders of the 335-horsepower engine with the throttle in the full open position, but forgot to retard the throttle to a one quarter position before starting the engine. When the engine started the airplane "leaped forward." The pilot quickly applied brakes, but the airplane accelerated across the taxiway and struck the opposing hangar and a parked airplane, which resulted in substantial damage to left wing. The pilot reported no preimpact mechanical malfunctions or anomalies that could have precluded normal operation.