Supplies of good clean water where, and when we need it – this is taken for granted by some, and is a pipedream for others. For most it depends in part on what people are doing up in the hills. The land in the hills may be used in ways that reduce the quantity and quality of water we get downstream. To get the water we want, we have traditionally relied on regulation, exhortation, cooperation or just keeping our fingers crossed. ~~What about some cold hard cash? What if the downstream beneficiaries of wise upstream land use and ecological management paid for these benefits? This is the idea of payments for watershed services. ~~But who will sell, who will buy, and under what conditions? Can this be good for ecosystems and for reducing poverty too? There is lots of theory about this. This report explores the evidence. It describes what the protagonists in a range of watershed sites around the world have learned in their efforts to set up such payment schemes. It concludes that these schemes are difficult to set up. But where they have been set up, they are generally beginning to do some good (there is not much evidence that they do any harm). More significantly, payment schemes or efforts to set them up have brought the current winners and losers into the open, and kicked-off debate on what can be done. What is now needed is for more ‘buyers’ to step forward, and for the shapers of payments for watershed services schemes to put hard-learned lessons from experience into practice at larger scales and ensure buyers get what they pay for, sellers get a decent price - and watersheds get a fair deal.