Between the handful of multinationals that dominate the international market, and the millions of informal enterprises that can be found in so many deprived urban neighbourhoods, are a growing number of local water companies finding new markets for water and sanitation. These range from the aguateros of Paraguay, to the water tankers of Accra, to the national and expatriate water companies that are increasingly competing for water and sanitation contracts in parts of Asia. This paper reviews the roles that they play, the markets they service, and the possibilities for getting them to provide better services for the urban poor.