On Flickr right now, a wide array of photos from New Orleans and many other affected areas following the devastation of Hurricane Katrina. In particular, have a look at this collection, amassed from various sources.
A post from Dave Winer: "On CNN, Aaron Brown asks what the city will look like when the water recedes. The correct answer … is that the water isn’t going to recede. The only way to get the water out of the city is to pump it out…" – consider this diagram (the cross-section, bottom right of the pic) to see why this comment is quite true.