Raymond Teller once said that the secret to fooling people is to put in so much more effort than the trick seems worth. It seems that the bods at Industrial Light and Magic followed his wisdom when concocting the effects for The Avengers. If you'd marveled at how seamless the team had blended shots of the Big Apple with the Chitauri invasion, then we've got a surprise for you -- almost none of it is real. Rather than shoot parts of the New York-based finale in the city (or any other city), the effects house created a 20-block "digital playground," complete with individually detailed office windows. Interested in learning just how much of those breathtaking set pieces were filmed in a green screen in New Mexico? Head on past the break.