We thank Professor Frank Wattenberg of the US Military Academy for providing the data for Exercises 6 and 7, as well as the photograph and Quicktime movie. Team members regularly demonstrate their precision skills by parachuting into the football stadium at home games. At Professor Wattenberg's request, one of the jumpers on September 30, 2006, carried a GPS device that recorded altitude, longitude, and latitude for the entire jump, thus giving a three-dimensional picture (of which we have used only one dimension here).