The pilot had completed several takeoffs and full stop landings in the airport traffic pattern. During a subsequent touch and go landing the pilot did not retract the flaps fully after landing. The airplane then became airborne prematurely at too low an airspeed during the subsequent takeoff attempt. When the pilot attempted to lower the nose and gain airspeed the left wingtip contacted the ground and spun the airplane to the right. The propeller dug into the turf just off the runway and the airplane came to rest inverted in a ditch. The airplane sustained substantial damage to the fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.