Comment Old news.. Caterpillar had these in the early 80's (Score 2) 64
When I was in the fifth grade (1982), I visited the Caterpillar International headquarters' IT center in East Peoria. For some damfool reason, they had a robotic mail carrier that followed a trail of chemicals laid down into the carpeting to wander around the floor, carrying mail and such.
This was before email, I guess, but no, I don't know why they had it either. It was boss, though.