CNN: It's been a cruel irony for ancient mariners and any thirsty person who has ever gazed upon a sparkling blue ocean: Water, water everywhere, and not a drop to drink. But imagine a coastal city of the future, say in 2035. Along with basic infrastructure such as a port, roads, sewer lines and an electrical grid, it's increasingly likely this city by the sea will contain a newer feature. A desalination plant. Thanks to improved technology, turning ocean water into freshwater is becoming more economically...