Mobile communications technologies are taking off across the world, while urban transportation and surveillance systems are also being rebuilt and updated. Emergent practices of physical, informational and communicational mobility are reconfiguring patterns of movement, co-presence, social exclusion and security across many urban contexts. This book brings together a carefully selected group of innovative case studies of these mobile technologies of the city, tracing the emergence of both new socio-technical practices of the city and of a new theoretical paradigm for mobilities research.