For the rapidly urbanising developing world, safe and affordable water is key to health and livelihoods, as well as meeting the Millennium Development Goals. But providing it demands innovative models. Where the context allows and the approach is appropriate, private sector involvement can generate win-win outcomes. Poor people can gain access to high-quality, affordable services, and companies can gain access to new and profitable business opportunities. Two examples of innovative ‘private’ water suppliers are the Manila Water Company’s Water for the Poor Communities (TPSB) programme, and the Water & Sanitation for the Urban Poor (WSUP) partnership. Both have a multisector approach to service expansion and provision, including partnerships with local authorities; strong community involvement in selecting, designing and operating options; appropriate service levels to reduce costs; and a flexible range of services. Many elements of these models are also replicable.