The folks at Truthout.org have set up a MAYDAY Mississippi Delta web page with round-the-clock information support for everyone impacted by Katrina. They also have lot’s of good sources available for the most up-to-date and expansive coverage possible.
These images from NASA’s Terra spacecraft show the effects of flooding in the New Orleans area (Before (left) and after (right)) (Photo: NASA/GSFC/MODIS)