Mobile learning has moved in the last decade from being a small, scattered research interest to being viewed by many international agencies as a way of delivering their humanitarian missions to the developing contexts of the global South. This paper explores and documents fundamental concepts and concerns that characterize or perhaps jeopardise the relationships between the "old" research communities and "new" policy maker communities working to improve the nature and scope of learning in the developing contexts of the global South using personal mobile digital technologies. As becomes apparent, these concepts and concerns are relevant and interesting across a broader range of domains, touching perhaps under-privilege and access to education and technology in both the global North and the global South, the uses of technology to extend, enhance and transform learning and the various pressures and determinants of policy-making and of the public funding of research. A list of references and further relevant reading is provided.