An overview is presented of anthropology's interest in voluntary association, from the classical influences and studies to sociological and anthropological work that illustrate recent trends from the last decade. Information is presented from the author's fieldwork with the Tucson Homeless Union and the Southern Arizona Coalition for the Homeless that describes the homeless situation in Tucson and the efforts of these groups, whose members share a dedication to improving conditions for socioeconomically marginal people through activist means of protest and civil disobedience. Marked by fluidity of membership and unique internal dynamics, these groups present a special case-study of voluntary associations as a means of urban adaptation through self-help and as a vehicle for social change. It is demonstrated how and examination of the values expressed by the existence and actions of these associations is useful in understanding the nature of society and the stability of the political system.