The Katrina Information Map is a Google Map to which people are adding markers for specific addresses in Louisianna. There are a few markers in Mississippi and Alabama, too. Click on a marker and you may find out whether there is flooding at that location. The creator has asked people to only add markers if they have information, but some are using the map to ask for help. Some are leaving phone numbers and email addresses in the balloon that appears when you click on the markers.
Wandering around the map gives me the impression that ther are still people wandering around New Orleans. Could emergency personnel be stopping to add markers to this map? Maybe they are if the addresses are important to themselves or their friends. I'm sure a lot of people would like to know.