The Lilypad, by Belgian architect Vincent Callebaut, is described as "a concept for a completely self-sufficient floating city intended to provide shelter for future climate change refugees."
Forget the dripping wet justification, it's still a pretty neat concept. Each 'lilypad' is "designed to house about 50,000 people in a man-made landscape that includes an artificial lagoon and three 'ridges'" -- producing its own energy through its "titanium dioxide skin" they're intended either to be moored near the coast, or "to float around on the ocean's Gulf Stream."
I can see a few being moored off the coast of Dubai.
More details here.