With the (slow) move towards hydrogen power, the water economy is coming. However, the relative disparity in the earth's stores of fresh water means that we either develop cheap efficient desalination solutions, or countries like Canada (with abundant fresh water supplies) will become the next middle east. Note: people point out that water, unlike oil, is available to anybody. This isn't quite true. Similar to the cost of drilling for oil, there will be a water processing cost involved to produce the hydrogen. Scarcity might still be an issue.