I saw a documentary on autistic savants yesterday (actually, it was the second of two parts, third one today on 3Sat, just in case you’re able to receive it and understand some German). The epsiode yesterday featured a man by the name of Stephen Wilthshire who’s got the ability to draw in detail just about everything he sees around him. As his sister said, he’s like a human videorecorder, able to to just go back in his memory and retrieve every single detail.
I found this resource that has the actual footage of the documentary I saw. In this segment, he’s shown drawing the whole of Rome’s inner city on a five meter strip of paper. He does this within two days, and after seeing the city from above in a helicopter for 45 minutes. It’s really quite amazing. Do check out the video.