This paper was prepared for the Planners Network Conference 2000 in Toronto. The focus of the paper is a re-conceptualization of community-based organizations from a model of a classic nonprofit institution to that of a social movement. Our observations are based on intensive evaluation of about 40 community-based arts organizations in Philadelphia involved in the Culture Builds Community initiative (1997-2001) of the William Penn Foundation. We argue that these small organizations have been colonized by business school consultants who want them to act and look like more established nonprofits. In our view, these organizations are better conceptualized as 'social movements' rather than—potentially—rational organizations. Changing the conceptual framework in this manner changes the definition of terms like 'capacity-building' and 'sustainability.' In addition, it shifts the 'unit of analysis' from individual organizations to the social networks in which they operate.