You'll find an article worth a visit to the dentist in the January 1997 issue of Popular Science. It tells a story from the 1960's cold war era. It seems that the only American who could get into the Soviet Embassy was the Xerox repairman. So the CIA and Xerox built a camera that took a picture of every copy that could be installed inside the 914 cabinet (where it would be invisble). Once a month, the repairman came by to do the ordinary cleaning and repair (those things broke down a lot). Part of the repair process exchanged the camera for a fresh load. The CIA could then read everything that was copied. The article suggests that other Xerox models had their own cameras. My back of the envelope (literally) computation suggests that one roll of 8-millimeter film would hold about 30,000 images. Martin Minow minow@apple.com