Computers are special in that they provide a new kind of stuff out of which to fashion virtual worlds to augment our perceptual, conceptual, and social interactions. They provide the most plastic medium for representation, communication, and interaction we have ever known. Ensuring that designs of computationally-based systems appropriately respect and effectively augment human needs and abilities is an intellectual challenge of the highest order. To meet this challenge requires careful continuing examination of the theoretical and methodological frameworks upon which we base our research activities. In this talk, I will focus on the theoretical and methodological choices we have made in our research and demonstrate how they have been instantiated in example current research projects on negotiated access, ubiquitous computing, gestures, ethnography of driving, and spatial multiscale tools for managing personal information collections.