The document discusses lessons learned from developing mobile phone tools for field projects in developing areas. It outlines challenges like unreliable infrastructure, high costs, and need for local participation. Key lessons are to engage local actors to own the technology through demonstrations and participatory design. Local resources should be trained for support. Systems should be customizable, integrated, and developed incrementally with stakeholder feedback. Usage levels, complex tasks, and unanticipated constraints must be considered. Mobile tools can streamline time-sensitive tasks using SMS reminders.