Jim Chuk's method of measuring toe in/toe out is spot on. Before alleged "hi-tech" methods (subject to various degrees of correct calibration) were use in aligning car front ends, spinning the tires against a chalk stick and then a fine point to make an accurate line to measure from with a trammel bar from was the standard TI/TO method; and highly accurate. Also like Jim's method which permits accurate measurements of each side from the centerline of the aircraft.