For more than thirty-five years the residents of Sydney, Australia woke up each and every morning to find the same one word written in yellow chalk in a perfect and elegant copperplate script. This single solitary word was written nightly on sidewalks, on streets, at train station entrances, and on buildings.  It was written just about everywhere in the city.  It was the mystery of Sydney.  It is estimated that the person who wrote this word did so more than one-half million times. But WHO would do this.  And, WHY?