This is a great story. A great example of how real improvements in people’s lives come simply from allowing opportunities. On this dry mountaintop, 36-year-old Bekowe Skhakhane does even the simplest tasks the hard way. Fetching water from the river takes four hours a day. To cook, she gathers sticks and musters a fire. Light comes from candles. But when Ms. Skhakhane wants to talk to her husband, who works in a steel factory 250 miles away in Johannesburg, she does what many in more developed regions do: she takes out her mobile phone. . . . Africa’s cellphone boom has taken the industry by surprise. Africans have never been rabid telephone users; even Mongolians have twice as many land lines per person. And with most Africans living on $2 a day or less, they were supposed to be too poor to justify corporate investments in cellular networks far outside the more prosperous cities and towns. But when African nations began to privatize their telephone monopolies in the mid-1990’s, and fiercely competitive operators began to sell air time in smaller, cheaper units, cellphone use exploded. . . .