http://en.wikipedia.org/wiki/List_of_humorous_units_of_measurement#Beard-second http://en.wikipedia.org/wiki/List_of_humorous_units_of_measu... probably best t

http://en.wikipedia.org/wiki/List_of_humorous_units_of_measurement#Beard-second http://en.wikipedia.org/wiki/List_of_humorous_units_of_measu... probably best to measure it in time. that is, a clean shave is length 0, time since last shave estimates length. If you use an electric shaver, the settings on the shaver associate to a known length. If you trim with scissors... that's a bit trickier.