[pxc]

One time when I was a kid, I rode with my dad while he gave a blind guy from our local Linux users group a ride home. With the windows rolled down and an occasional question, he gave us turn-by-turn directions to his house, based on the map he had in his head of the route between the venue and his house, plus the way traffic sounded as it echoed off of various key buildings and streets that were landmarks for him.