AS A PITTS SPECIAL, N66D, WAS IN THE TRAFFIC PATTERN TO LND, A CESSNA L-19E TOWPLANE, N4431B, WAS ON THE 1300' GRASS OVERRUN NEAR THE APCH END OF THE RWY WITH A GLIDER BEING READIED FOR TOW. THE GLIDER (SAILPLANE) WAS A GROB 103, N226BG.THE PLT OF THE PITTS STATED HE NOTICED SVRL GLIDERS & TOWPLANES PARKED ON/NEAR THE OVERRUN, BUT SINCE THE USUAL PRACTICEWAS TO PARK SUCH ACFT IN THAT AREA, HE DID NOT CONSIDER THEIR PRESENCE AN INDCN OF IMMINENT TAKEOFF. AS THE PITTS CONTD ON FINAL APCH, THE TOWPLANE & GLIDER STARTED TAKING OFF. SHORTLY AFTER THE TOWPLANE LIFTED OFF, IT & THE PITTS CONVERGEDVERTICALLY & COLLIDED. THE PITTS THEN ENTERED AN UNCONTROLLED DSCNT & CRASHED IN A STEEP NOSE DOWN ATTITUDE, BUT THE PLTWAS SECURED IN THE ACFT BY A 5 POINT HARNESS & A LAP BELT & SURVIVED. THE TOWPLANE'S LEFT WING TIP WAS DAMAGED, BUT THE PLANE CONTD FLYING & LNDD SAFELY. RPRTDLY, THE WING WALKER FOR THE GLIDER WAS INEXPERIENCED & DID NOT CONFIRM THE LNDG TRAFFIC OR SIGNAL FOR THE TOWPLT TO DELAY THE TAKEOFF.