The convergence of mobile communications and handheld computers offers the opportunity to develop technology that will assist individuals and groups to learn anytime, anywhere. We describe the theory-informed design, implementation and evaluation of a handheld learning device. It is intended to support children to capture everyday events such as images, notes and sounds, to relate them to web-based learning resources, to organise these into a visual knowledge map, and to share them with other learners and teachers. A working prototype system, for children aged 9–11, is discussed and evaluated, as an exemplar of personal mobile systems for life-long learning.