According to the pilot, he and his friend had pre-arranged a formation flight to attend an air show. He stated that he performed formation flying frequently. While on short final to the runway, he lost sight of the lead airplane in the formation and veered left in an effort to regain visual contact. While sidestepping approximately 20 feet above the ground he stalled the airplane and applied full power to recover. The left wing tip contacted the ground and the airplane landed hard and skidded for about 100 yards. An inspector with the Federal Aviation Administration inspected the airplane and reported structural damage to the left wing and the engine was significantly damaged.