Amateur Radio operators compete and often keep track of how far away the people are that they make contact with. In the late 50s, folks created a grid system for Europe so people could quickly transmit approximate location. In 1980, amateurs began to adopt a new system, the Maidenhead Locator System, which describes a world-wide grid system.
I found a fun Google Maps dealie that shows you the Maidenhead Locator System overlaid a more traditional map.