Thispaper describes our design and implementation of a computer augmented environment that allows users to smoothly interchange digital information among their portable computers, table and wall displays, and other physical objects. Supported by a camera-based object recognition system, users can easily integrate their portable computers with the pre-installed ones in the environment. Users can use displays projected on tables and walls as a spatially continuous extension of their portable computers. Using an interaction technique called hyperdragging, users can transfer information from one computer to another, by only knowing the physical relationship between them. We also provide a mechanism for attaching digital data to physical objects, such as a videotape or a document folder, to link physical and digital spaces.