This PhD study is at the intersection of people, place and technology and pioneers innovative development approaches towards interactive social networking systems informed by community, social and urban studies and employs human-centred and participatory design methods. The project delivers a greater understanding of the potential for internet-based systems to support and facilitate social networks of urban residents and the role of those networks to foster neighbourhood identity and social capital. Departing from conventional notions that regard communities as collectives, this study builds upon more contemporary interpretations of community inherent in Castells’ and Wellman’s theories of the network society and networked individualism. The thesis challenges the view that a mere re-appropriation of applications used to support dispersed virtual communities of interest is adequate to meet the place and proximity-based design requirements that community networks in urban neighbourhoods pose. The overarching principal research aim of the study is to propose new ways of conceptualising the roles of social networks of urban residents to better inform the design of new technology facilitating urban neighbourhood developments. Addressing this aim requires a new understanding of the roles of social networks of urban residents. The study sets out to critique the implicit theories underlying technology design in this area and to propose a more appropriate theory based on recent developments in the field and empirical findings from the study. The key research questions are: 1. What theoretical model can better represent social interaction of residents in inner-city apartment buildings? 2. How can relevant research methods be adapted to take the network qualities of social interactions into account? 3. What are the implications of a new understanding of social networks for the design of technology that supports the growth of neighbourhoods? 4. What are the implications of a new understanding of social networks for an urban architecture that supports the growth of neighbourhoods? Within a framework of action research, the study follows a case study approach of three different inner-city residential apartment complexes in Brisbane. Research methods are mostly qualitative and ethnographic and include surveys, focus groups, participant observation and interviews, as well as participatory design. The study delivers innovative outcomes on three levels: 1. Theoretical innovation with an analytical translation of Wellman’s notion of networked individualism and a conceptualisation of the communicative ecology model into the context of system design that supports social networks of residents in inner-city apartment buildings; 2. Methodological innovation with the presentation of Network Action Research, an addition to the action research family which pays particular attention to the network quality of social formations in communities; 3. Empirical innovation with research findings which indicate that the key factors influencing the successful design and uptake of interactive systems to support social networks in urban neighbourhoods. They include the swarming social behaviour of urban dwellers, the dynamics of their existing communicative ecology, and the serendipitous, voluntary and place-based quality of interaction between residents on the basis of choice, like-mindedness, mutual interest and support needs. Findings are presented in three parts to audiences interested in people, technology and place. Drawing on social, urban and computer sciences, this research project delivers insights which will assist efforts to facilitate urban neighbourhood community building with new media and network ICTs. Understanding the issues and challenges as well as opportunities and strengths in forming a local meshwork of social networks will help Australians negotiate the complex web of daily choices, access a greater social safety net, and participate in the socio-cultural and socio-economic life of their city. This in turn will contribute to greater social inclusion, urban sustainability and healthier local economies.