Stephen Wiltshire: the Human Camera.

From the video clip description:

Stephen Wiltshire [wiki] has been called the "Human Camera." In this short excerpt from the film Beautiful Minds: A Voyage into the Brain, Wiltshire takes a helicopter journey over Rome and then draws a panoramic view of what he saw, entirely from memory.

Hit play or go to Link [YouTube] | Stephen Wiltshire's website - via lnkage