Only superlatives seem appropriate to describe the mobile phone 'revolution' – its impact and its potential – in Africa. Mobile phones are almost always the cheapest and quickest way to communicate, particularly when fixed-line phones and broadband internet are underdeveloped and dependent upon expensive infrastructure. The continent is home to 350 million mobile phone subscribers,1 and their numbers are growing faster than anywhere else in the world. The ubiquity of mobiles is matched only by the ingenuity of their users. From shantytowns to remote villages, mobile phones are being used to transfer money, monitor elections, and deliver public health messages. A large informal economy has also emerged to support the mobile sector, with people selling airtime, charging and fixing mobiles, and renting them out. Africa is truly a...