The first truly wearable computer didn't appear until 1961 - and, of course, it was created to help a pair of cunning mathematicians cheat at roulette. Edward O. Thorpe and Claude Shannon concealed a timing device in a shoe which could fairly accurately predict where the ball would land on a roulette table. The number was communicated via radio waves to the gambler with a great deal of success - Thorpe reported a 44 per cent increase of winning bets. Other mathematicians developed similar machines, proving so successful that the state of Nevada - where Las Vegas resides - passed a law prohibiting them in 1985
Just as the abacus was a precursor to the modern computer, the abacus ring was the forefather of today's wearables. This marvellous 17th-century Chinese implement allowed bean counters to perform mathematical tasks without using the written word, instead moving tiny beads along nine rows - and there were no issues with battery life either.