Actually there are two ways of doing it without using triangulation. You can measure the time delay, assuming the processor is fast enough. The speed of light is 3*10^8 meter/second. If you have a 80MHz clock on your processor (Propellor with an external clock), that means your step distance is 3.75 meters per cycle (and a minimum distance of 3.75 meters too), plenty close for me, since I will be using UltraSonic's for close distances that work up to 6 meters. The other method is to modulate the laser with a frequency, then you can determine the distance using the properties of the Doppler effect, as long as you're relatively moving
