American warplanes are being equipped with electronic tags, so that aerial tankers can automatically note who got what when they are refueled in flight. These records used to be updated manually, which led to errors, and a distraction for the boom operator who was handling the refueling operation. The electronic tag is called RFID (radio-frequency identification), and it's been in development for years, to replace bar codes (which was the previous revolution in keeping track of stuff). RFID uses small labels containing a cheap (less than a buck now, headed towards pennies each) electronic device that contains information about what...