Men look at mobile phones at the Adjame market in Abidjan, Ivory Coast. The market for mobile telephones in developing countries has grown quickly, and now Facebook and Google are trying to get users to use the Internet on their devices. Issouf Sanogo /AFP/Getty Images hide caption

itoggle caption Issouf Sanogo /AFP/Getty Images

A phone booth serves as a free Wi-Fi hot spot in New York City's Columbus Circle. Anna Solo/ hide caption

itoggle caption Anna Solo/