When we think of mobility in technical terms, we think of topics such as bandwidth, resource management, location, and wireless networks. When we think of mobility in social or cultural terms, a different set of topics come into view: pilgrimage and religious practice, globalization and economic disparities, migration and cultural identity, daily commutes and the suburbanization of cities. In this paper, we examine the links between these two aspects of mobility. Drawing on non-technological examples of cultural encounters with space, we argue that mobile information technologies do not just operate in space, but they are tools that serve to structure the spaces through which they move. We use recent projects to illustrate how three concerns with mobility and space--legibility, literacy, and legitimacy--open up new avenues for design exploration and analysis. r 2008 Elsevier Ltd. All rights reserved.