A clever person named Alex Tingle has mashed up NASA elevation data with Google Maps to help visualize what various degrees of sea level changes would do to our coasts. Here's the map for Boston under a 7 meter sea-level rise (the scientists' prediction plus an extra meter from a hurricane storm surge, suppose). The airport turns into a salt marsh, the quadrangles of MIT and Harvard become mud flats, and much of the Emerald Necklace turns blue.
Portland fares better, but whole neighborhoods (Knightville, Bayside, and Baxter Boulevard) are still expected to drown.
These maps show that every coastal city in the world can expect Katrina-scale floods in the upcoming century. Meanwhile, Reuters reports that Bush's next State of the Union address will outline a global warming policy based on appeasement instead of mandatory emissions caps. And Halliburton is cornering the market for hip waders.