As I was boarding a bus last week, I met a woman who had a great big dog. The dog was wearing a jacket which read "I AM BLIND", so I assumed that the woman was blind, and that this was her guide-dog.
However, I soon realized it was the dog who was blind! The woman gave him spoken Instructions; go forward, go left, come around this obstacle - and the dog obeyed, and smiled. This wasn't guide dog - he was a guided dog!