From the letters page of today's Wall Street Journal:

Sharon Begley's Science Journal column Friday ("Man-Made Mistakes Increase Devastation of 'Natural' Disasters") describes how the levees have contributed to the disaster at New Orleans. Some new ideas are needed to save the city because the levee model will just lead to worse catastrophes in the future. Why not accept the fact that New Orleans is a city below sea level and make the most of it? Venice has done it and is one of the favorite tourist destinations in the world. Converting downtown New Orleans into a city of canals and gondolas would mark the renaissance of this beautiful city.

Obviously I have no idea if this would work or not, but I find the idea weirdly compelling.