One trick used by the Serbs during the Kosovo campaign was to roll out 20-foot-wide strips of black plastic (which looked like roads from three miles up) which had pictures tanks and other armored vehicles spray painted on them. The Serbs knew that it would be 12 hours between the appearance of a lone photo-recon plane and the subsequent air strike, and used the time to relocate the real unit and replace it with dummies.--Stephen V Cole