World War II "Ghost Army"

Boing Boing posted this trailer about the newly released book, The Ghost Army of World War II.  The Ghost Army was a U.S. military unit whose sole purpose was to use deception to convince the Germans that this small unit of troops was an entire army.  The work of this unit, combined with British intelligence and other operations, convinced Hitler that the D-Day invasions of Normandy were a diversion, and that the real invasion would come at the Pas de Calais.