First, we used PDAs combined with GPS receivers and WiFi networking to access a virtual world when moving through the physical world, creating an experience called Unearthing Virtual History in which mobile participants searched a physical environment for buried digital artefacts. Second, we developed a portable mixed interface for outdoors called the augurscope - a tripod-mounted display that can be wheeled to different locations and rotated and tilted to view a virtual environment that is aligned with the physical background. Two generations of the augurscope were deployed publicly at Nottingham castle where members of the public used them to visualise how the medieval castle would have appeared in relation to its modern counterpart. Third, we experimented with using 'light based' interaction techniques, including projecting shadows of online avatars onto the city streets at night and also using video-tracked flashlights as pointing devices. Video tracked flashlights were used by two hundred members of the public to trigger ghostly voices in the caves under Nottingham Castle and were also used to create a series of interactive posters and wall-displays. |