Handheld devices are being used increasingly in schools and higher education. Many researchers assume that the use of these devices will exert considerable impact on educational practices. However, to date, it appears that such use has not been sustainable and transferable. The impact of educational uses of handheld devices does not yet seem apparent. This article classifies educational applications of handheld devices into six categories with sub-categories, drawing on information found in 73 papers and research reports in journal articles, 38 papers in international conference proceedings, and 12 book chapters about handheld applications. It also discusses the consequences of handheld technologies for educational uses. (Contains 1 table.)