We begin by reviewing current spatial approaches to CSCW (mediaspaces, spatial video conferencing, collaborative virtual environments and telepresence applications) and classifying them along the proposed dimensions of transportation, artificiality and spatiality. This classification leads us to identify new shared space applications; so called mixed realities. We present an example of a mixed reality called the Internet Foyer, an application which provides a unified entry point into an organisation's physical and electronic environments and which supports awareness and chance encounters between the occupants of physical and synthetic space.