Using computer technology to support authentic learning activities produces effective learning environments when two situations occur-the teacher understands how technology tools can be used in delivering instruction and the students have access to the tools anywhere and anytime. The use of handheld computers in classrooms hints at the possibility of providing computer access for every student in classrooms across the country; and with teachers developing a repertoire of activities based on activity structures designed to deliver instruction that seamlessly integrates technology into a variety of learning situations, students everywhere can participate in learning environments that support interactive, creative, and learner-centered scholarship. This article describes the use of activity structures to seamlessly integrate handheld computers into instructional designs that promote these types of learning environments.