As PDA's becomes increasingly accepted in clinical settings, medical schools are following suit by requiring or recommending PDA's to enhance students' clinical knowledge and skills. This paper examines the implementation of a PDA requirement at a leading US based medical school over three years. It explicates the complexity of diffusing a nomadic technology even in an educational environment generally receptive to new technologies. The outcomes of three years of specialized design and development for PDA's illustrate the uniqueness of handheld technologies, requiring a much needed theory of mobile computing. The authors conclude that while PDA's are successfully integrated in clinical settings, their value in medical education is less unambiguous.