The best solution to world thirst may be desalination

Water may be flowing on Mars, but where we really need it is here on Earth. Over 75% of our planet's surface is covered in water, yet 2 billion people worldwide reside in water-stressed countries. With fresh water accounting for a meager 3% of Earth's total water supply (and the vast majority of it locked up in… » 8/04/11 6:28pm 8/04/11 6:28pm