Britain's computer revolution began in a tea shop. Lucy Kellway of the Financial Times, disovers how the first machines - LEO (Lyons Electronic Office - were designed to add up the receipts from sticky buns and pots of tea. Plus, we meet Toomas Hendrick, the president of the world's first truly digital nation - Estonia. He explains how investing in communications - hi-tech telephone switches rather than roads transformed the nation's economic prospects. Plus, one of the founders of YouTube explains why the companies that design global technology insist on basing themselves in Silicon Valley.