The [link|http://www.digitalglobe.com/images/katrina/new_orleans_msi_aug31_2005_dg.jpg|after] picture is at [link|http://www.digitalglobe.com/sample_imagery.shtml|Digital Globe]. It's 4062x4544 (3.3 MB), from yesterday. Zoom in and see all the water. :-(

[link|http://earth.google.com/|GoogleEarth] has some wonderful high-resolution before imagery as well.

Cheers,
Scott.