Actually, these headband things were invented over 2000 years ago when Alexander the Great was trying to conquer the known world. He discovered early on that large-scale troop movements were impossible to coordinate without some sort of color coding. He and his generals came up with headbands that changed color after varying amounts of time, so he could tell some of his troops that they were in reserve for an hour, and had to attack when the headbands turned green, while others had to attack after say three hours when their headbands turned orange.

This of course, we know today as Alexander's Rag Time Bands.


TEd