The earliest form of non-spoken communication — humans are believed to have started speaking to each other about 100,000 years ago - is the use of drawing. Around 40,000 years ago, people in Spain and Indonesia were making paintings on the walls of caves, showing aspects of their dally lives. This is important because it indicates growing human intelligence. The representation of words using pictograms naturally followed on from this, which was an important step in the development of the kinds of alphabet we know today. Writing using pictograms or early alphabets was first done on stone and then on papyrus in Ancient Egypt. The use of papyrus meant that messages could be transported from one place to another. By 780 BC, the Greeks were sending short handwritten messages by carrier pigeon. In this way, they conveyed messages far more quickly than people had been able to do before. The first proper postal service was created by the Persians in the Sixth century BC, Horse riders used to carry documents from one posting station to another. Together they would cover distances of 2,000 kilometres or more, in a matter of days. But the real revolution in written communication came with the invention of the printing press in 1440 AD. Up until then, people had been reading handwritten documents. That must have been an extraordinary time in history — a bit like the introduction of the Internet thirty years ago — because almost immediately.