According to the pilot, during the take-off roll and initial climb, he felt he did not have enough airspeed to climbout and make it over a hill that was in the distance. He aborted the takeoff, landed the airplane, and attempted to stop the airplane before the end of the 2,400 foot runway. The airplane continued off of the departure end of the runway and collided with a ditch. A post-accident examination of the airplane revealed that it sustained substantial damage to both wings and the firewall. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.