Is it possible to imagine novel forms of urban planning and of public policies regulating the ways in which people use city spaces by listening to citizens’ expressions, emotions, desires, and visions, as they ubiquitously emerge in real-time on social networks and on other sources of digital information? This chapter presents the theoretical and methodological approach, the investigation and research phases, the design and prototyping processes constituting the ConnectiCity initiative, a collaborative, multi-disciplinary series of projects in which artists, scientists, anthropologists, engineers, communicators, architects, and institutions participated to the design of innovative ubiquitous and pervasive systems which were able to transform the ways in which the concepts of urban planning and city-wide decision-making are defined. Novel forms of urban life were imagined, in which cities became the time/space continuum for multiple, stratified layers of information expressing the ideas, goals, visions, emotions, and forms of expression for multiple cultures and backgrounds, producing new opportunities for citizenship: more active, aware, and engaged in the production of urban reality, and in the transformation of city spaces into possibilistic frameworks.