There was a report some time ago that researchers have developed a way to duplicate keys given only a photograph. When I read this story, I was reminded of an incident that occurred to a colleague of mine.
He accidentally locked his keys in his car and called a locksmith. Frustratingly, the keys were sitting right there on the driver's seat. The locksmith arrived and assessed the situation. "Well, since you already paid for me to come all the way out here, how would you like a spare key?"
"Huh? What do you mean?"
The locksmith looked at the key on the driver's seat, studied it intently for a few seconds, then returned to his truck. A short while later, he returned with a freshly-cut key, which he inserted into the door lock.
The key worked.