There's a fascinating report on global water supplies in the Christian Science Monitor. Global water markets are a $500 billion annual business and growing. Forty six nations are susceptible to violent conflict over water by 2025. Canada, which holds 20% of the world's fresh water, voted to take water out of NAFTA, to prevent thirsty Americans from piping it south. [right: Crescent Lake, AZ; copyright Michael Collier]