The pilot was on the second leg of a cross-country flight when the airplane's engine momentarily decreased in power and then returned to "normal." The pilot observed that the airplane's left fuel tank was indicating empty and the right fuel gauge was indicating less then one forth a tank. While attempting to return to the departure airport, the engine "sputtered" and lost all power. The pilot elected to leave the landing gear and flaps retracted while executing a forced landing in a ditch. The airplane came to rest in an upright position and the pilot and passengers exited unassisted. The airplane's fuselage and left wing sustained structural damage. An on-site visual inspection of the airplane's fuel tanks revealed a residual amount of fuel. The pilot further reported that he did not perform a visual inspection of the airplane's fuel quantity before departure.