Handheld devices have the potential to make a large impact on K-12 educational settings, due to their relative low cost, high mobility, and interactive learning capabilities. This article, the outcome of a large-scale project examining the use of handheld computers, examines how handheld computers can improve teaching and learning, what educational activities are possible, and what is still missing in this new technology. Data collected from student and teacher surveys indicate that immediate accessibility for all students, possibilities for student collaboration, and the use of technology as an integrated (not separate) part of the curriculum as the strong points of handheld devices in K-12, while there is a need to resolve specific hardware/software issues, develop handheld pedagogy and professional development, as well as handheld-related research to inform teaching practices.