Number 40: Personal computingWhat if every child in the world had a laptop? A few years back, it would have seemed a ridiculous question. Nicholas Negroponte and the MIT Media Lab are making it possible. He set out in 2005 to design a radically less expensive computer to distribute worldwide. His nonprofit, One Laptop per Child, says 2 million children in 31 countries, from Peru to Mongolia, are using its stripped-down PCs. The organization, which has yet to get the price down to $100, is now working on a tablet computer.