The airplane was parked on the ramp and the pilot reported that he had difficulty starting the engine. On the third attempt, the engine started at a high rpm, and the airplane rolled forward. The pilot applied left rudder to avoid a fuel truck, reduced the throttle to idle, and applied brakes; however, the airplane's forward momentum and engine rpm still seemed high. The pilot subsequently shut-down the engine; however, the airplane struck a parked, unoccupied airplane, and sustained substantial damage to its right wing. Examination of the airplane, which included the brake and throttle control systems did not reveal any mechanical malfunctions that would have precluded normal operation. The pilot also reported that he did not experience any preaccident mechanical malfunctions or failures.