Ubiquitous computing is unusual amongst technological research arenas. Most areas of computer science research, such as programming language implementation, distributed operating system design, or denotational semantics, are defined largely by technical problems, and driven by building upon and elaborating a body of past results. Ubiquitous computing, by contrast, encompasses a wide range of disparate technological areas brought together by a focus upon a common vision. It is driven, then, not so much by the problems of the past but by the possibilities of the future. Ubiquitous computing’s vision, however, is over a decade old at this point, and we now inhabit the future imagined by its pioneers. The future, though, may not have worked out as the field collectively imagined. In this article, we explore the vision that has driven the ubiquitous computing research agenda and the contemporary practice that has emerged. Drawing on crosscultural investigations of technology adoption, w...