A landing gear malfunctioned on a flight headed into Lindbergh Field. Passengers credited the flight crew for keeping them informed and the pilot's "quick thinking" that may have saved lives when he realized there was trouble and *manually-lowered* the landing gear from inside the cockpit. The Delta flight was enroute to San Diego from Minnesota-- when a hydraulic problem caused the landing gear to malfunction-- but the plane landed safely at Lindbergh Field.