By Bill Bulkeley, Cisco
When the third Harry Potter book appeared in 1999, one of the startling bits of wizardry at Hogwarts was a magical map that labeled people walking around the school and showed hidden passages and how to get into them.
Today, the wizards developing apps for smart phones are doing similar things with augmented reality.
AR, as it is known, is a technique for enhancing the real world with digital information automatically delivered to a viewing screen. A classic example: in televised football games, the digitally-created yellow line that shows how far the ball carrier needs to rush to get a first down.