During cruise flight, the pilot experienced a loss of engine power of one engine. Using standard engine out procedures , the pilot experienced difficulty identifying which engine had lost power. However, without the knowledge of the pilot, the passenger attempted to assist the pilot in maintaining directional control after initial loss of engine power by applying right rudder. In an effort by the pilot to regain full engine power, the second engine lost power. The pilot selected a nearby landfill for an emergency landing. During the emergency landing, the main landing gear collapsed. After the pilot and passenger exited the airplane, the passenger told the pilot that he had applied right rudder after the initial loss of engine power. Post-accident examination of both engines failed to disclose any abnormalities and 35 gallons of fuel was recovered from the fuel system.