There is a much better way to build a computer that can serve the rural poor, if you're willing to pay for it. The San Francisco nonprofit Inveneo builds Linux boxes with solar panels, a bike generator for cloudy weather, and a directional WiFi antenna that can get you on the Internet via satellite from almost anywhere. Inveneo can build one of these setups for $1,800, but they're only making a small handful. Increase the production run to tens of thousands and the price would drop precipitously.
Inveneo is building these machines to be durable, upgradable, and to run on renewable energy. Sure, they're not laptops, but they give anyone access to cheap worldwide voice communication. That's something that even someone who is illiterate can take advantage of—without having to use a hand crank.