Mobile phone adoption has grown rapidly worldwide, with over 4.5 billion subscribers in 2009. While mobiles show promise for development, some key issues remain regarding their impact and potential. Specifically, there is a lack of open platforms and applications at scale, as well as limited knowledge about what works best in different contexts. Moving forward, targeted research, innovation marketplaces, strong intermediary organizations, and user adoption studies are needed to help mobile technology have transformative impact in a sustainable way.