I am currently reading Malcolm Gladwell's 'Blink' a book about the conscious and unconscious mind, first put forward by Freud in the late 80's. One section of the book that is interesting is when he is talking about different signals that as humans we give off depending on our personalities. He cleverly relates this back to World War 2 and talks about how morse code was used to communicate. He says that different operators where known for their different styles in which they were translating code worldwide. The interpreters who were used to translate this code were then able to identify over time who it was who was sending out the signal from there personal style of 'writing' (longer dashes or shorter dots for example). This in turn meant that they could track where a certain squadron was based on the intel that was being distributed. If they were unsure about where a squad was they would track the morse code to distinguish if they were in Italy, or still in France. Very clever.