The solo private pilot was landing a tailwheel-equipped airplane on a rural grass runway. At the mid-point of the 1,000 foot long runway the airplane was still airborne, but the pilot reported that he elected not to go-around because of trees and power lines on the departure end of the runway. The airplane was still moving about 20 mph when it impacted obstructions at the end of the runway. The airplane sustained substantial damage to both wings, the right aileron, and the upper fuselage. The pilot also reported that there were no preaccident mechanical problems with the airplane.