Poor villages in Thailand have found a great way to improve their lives and make a little money. They generate electricity using micro-hydroelectric equipment, and then sell on any surplus to neighbouring settlements. Instead of waiting for the state-sponsored electricity grid to get to them, they're doing it themselves. Scotland has found a winning formula for keeping its rivers unpolluted and full of wild salmon. Rather than rely on public ownership and government clean-up schemes, fishing rights are bought and sold. So the owners have a powerful incentive to make sure that streams are kept clean and well-stocked. Want to...