Researchers have noted that technological innovation and advocacy has far outpaced research on how teachers learn to incorporate technologies into their classrooms, perhaps leading to slower integration of technologies into schools. Therefore, the purpose of the study was use cognitive developmental learning theory to examine shifts in preservice teachers' perceptions about using personal digital assistants (PDAs) to enhance instruction in physical education, and to identify factors leading to their shifts in thinking. We used interpretive ethnographic methods to study seven preservice teachers as they participated in a six-month project aimed at integrating PDAs into their teaching. We describe two main research themes. First, we found substantial shifts in the teachers' thinking about PDAs and teaching. Initially, they described strong skepticism toward PDAs based on their visions of education, views of PDA quality, and technological expertise. However, by the end of the project, they strongly supported and valued PDAs in their teaching. Second, four factors seemed to play key roles leading to their shifts in thinking: (a) "time to play," (b) an available and credible instructor, (c) real-world field experiences, and (d) an informal peer learning community. The discussion centers on explaining these findings in light of current technology research and theory, and their implications for teacher education. (Contains 1 table.)