More than 50 new tablet computers are expected to debut at the annual Consumer Electronics Show in Las Vegas this week. But only one is meant for people in the poorest regions of the world, and comes with a hand crank as an accessory. Known as the XO 3.0, the rugged green and white device has an eight-inch screen and was designed by the nonprofit One Laptop Per Child, which in 2008 launched the XO laptop, a device for people who are normally far from the minds of most computing companies. At a press preview held before the official opening of CES on Tuesday, OLPC's chief technology officer, Edward McNierney, told Technology Review that the new device could be used by children as young as five. "We're trying to provide a low-power, low-cost environment for education," he said. "One of the things we're working on now is software experiments to see if children in completely illiterate communities, who don't go to school, can teach themselves to read."