16 december 2012 - Nairobi, Kenya - Customers at an M-Pesa service outlet in Gatina slum, Nairobi. M-Pesa is a mobile-phone based money transfer and microfinancing service for Safaricom and vodacom, the largest mobile network operator in Kenya and Tanzania. Currently the most developed mobile payment system in the developing world, M-Pesa allows users with a national ID card or passport to deposit, withdraw, and transfer money easily with a mobile device. Photo credit: Benedicte Desrus