On June 2, 1998, at 1830 central daylight time, a Sheets Kitfox II, N487JS, piloted by a private pilot, was destroyed when it impacted the terrain, following a loss of control during takeoff from runway 32 (2500' x 45', dry, asphalt) at the Greenfield Municipal Airport, near Greenfield, Iowa. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot sustained minor injuries. The one passenger reported no injures. The local flight was originating at the time of the accident. According to the pilot's written statement, the pilot was attempting a normal takeoff at the time of the accident. The pilot stated that he was using 20-degrees of flaps for takeoff, which is not the normal takeoff configuration, because he was testing a new takeoff technique he had seen in an aviation publication. The piloted stated that the aircraft became airborne, sooner than expected, and drifted to the right of the runway centerline. While the aircraft was drifting across the runway it impacted the ground approximately 30' from the runway centerline. In a telephone conversation with the pilot, he stated that the accident could of been avoided if he had built up additional airspeed before liftoff and after liftoff kept the aircraft low in ground effect.