What constitutes the "urban" today? How can it be described? That urban life has become increasingly entangled with mobile, embedded, and networked media, communications and information technologies is commonplace. Yet we often refer to these conditions in terms of social interactions mediated by an immaterial informatic space overlaid onto a physical, material network of buildings, sidewalks, streets and public squares. Doing so not only maintains established dichotomies (between virtual and actual, material and immaterial, social and physical), but also elides some of the more subtle and nuanced modes of encounter and relationality that make up a contemporary urban experience composed of actors, practices and situations that are recurrently performed and enacted. How does a situation matter? What action does it call for? How are its priorities revealed?