The Guardian has a photo feature of Cities at Sea of the present and future. From the "floating ecopolis" of Project Lillypad, which looks like something straight out of Sid Meier's Alpha Centauri, to the Netherlands floating homes which go up and down with the floods.
There's even the aircraft carrier-like Freedom Ship, which goes to show that the rich won't have to leave Earth as Ben Elton predicted in Stark. Like Noah and the Ark, the Freedom Ship will save the righteous rich while the corrupted poor drown. At least, that's what they think. Conceived to hold 60,000 people, it's nothing a freak wave can't fix.