This chapter describes the social and digital ecologies of mobile work places. Social and digital ecologies describe human and technological relationships that exist in a particular place. For example, human-to-human, human-to-computer and computer-to-computer relationships might be taken into account as being part of a network of people and technological artifacts. Mobile work places are non-traditional work settings including cafes, parks, airport lounges and other public and semi-public places. In recent years, such locations have become important work places for mobile professionals, in particular, among remote workers, telecommuters, self-employed and freelance workers, and entrepreneurs. The declining cost and widespread use of laptop computers, mobile phones and personal digital assistants (PDAs) as well as the increased deployment of wireless fidelity (WiFi) hotspots contributes to the usefulness of mobile work places. Drawing on a year-long ethnographic study of mobile work places in New York, I will argue that these locations are intense sites of informal interaction, social support, collaboration and community. In addition, I will show how mobile work places blur, and often reverse or contradict, traditional dichotomies such as work and play, online and offline, public and private, presence and co-presence, individual and community, and local and global. In contrast to media representations of mobile work that focus on freedom, convenience and ‘anytime, anywhere’ use of mobile and wireless technologies, I will illustrate the ways in which mobile work places support emergent and rapidly transforming occupations. I will explain the public nature of mobile work and the deliberate reasons that mobile professionals choose mobile work places. Finally, I will conclude by arguing that mobile work places are examples of the (re-)emergence of a community form of organizing that coexists with hierarchical, market and network forms of organizing.