In May 2005, a renowned British hoaxer, known only as Banksy, placed this alleged piece of 'cave art'--showing a prehistoric man with a shopping cart--in the British Museum in London. Titled 'Early Man Goes To Market,' the piece hung on a wall for three days before anyone questioned its authenticity. Banksy, who has pranked museums around the world, even provided a caption under his masterpiece: 'This finely preserved example of primative art dates from the post-Catatonic era...' How did no one spot such an obvious hoax for three days? Said a chagrined museum representative, 'It looked very much in keeping with the other exhibits.'