Who built the first programmable robot? It's almost impossible to tell, and most people would put good money on Leonardo da Vinci. But now Noel Sharkey, a computer scientist at the University of Sheffield, UK, has traced the technology way back to ancient Alexandria.

In about 60 AD, a Greek engineer called Hero constructed a three-wheeled cart that could carry a group of automata to the front of a stage where they would perform for an audience. Power came from a falling weight that pulled on string wrapped round the cart's drive axle, and Sharkey reckons this string-based control mechanism is exactly equivalent to a modern programming language. He describes it in this week's issue of New Scientist magazine.

They should have kept developing this.. we'd probably have mecha all over the place by now.