The increasing capabilities, low power requirements, and form factor of cell phones (and their disappearing cousins the PDAs) have pushed mobile computing to the forefront. Nowhere is this more evident than in third world countries -- the ubiquity of cell phones has the potential to bring the benefits of computing to places that could never before support it. This hardware revolution, however, needs a software revolution to match: we must develop software that can harness this flood of computing power to aid development and public health. In this session, Selanikio talks about his experience as a public health doctor and technologist, and how he is combining those skill sets to save lives and fight measles, malaria, and malnutrition in countries poorer than you can imagine.