Computers will not always be used as glorified typewriters - the future of human-computer interaction is not in typing words and dragging icons.  How are we to interact with technology as it becomes more powerful and ubiquitous? How can we make technology truly user-friendly and accessible to all? We need to move toward "perceptual user interfaces" (PUIs) - highly interactive, multimodal interfaces that are modeled after natural human-to-human interaction. This requires better understanding of human perceptual capabilities as well as improved machine perception. Most importantly, it requires researchers from various disciplines, including vision, speech, UI, learning, haptics, cognitive psychology, and others, to cooperate deeply. From the Series:CSE Colloquia - 1999