After flying over London in a helicopter, Stephen Wiltshire could reproduce by memory a detailed aerial illustration of a four-square mile area in under three hours that included 12 historic landmarks and 200 other structures. He has done similar illustrations of New York, Tokyo, San Francisco, Frankfurt, and is currently in Madrid doing the same. On his way back to London, he will be stopping in Dubai, Jerusalem and Sydney. He was diagnosed autistic with Savant syndrome when he was 3…