The Association of American Geographers is organizing an online clearinghouse and establishing a fund to help geography departments and others impacted by Katrina. If you would like more information or would like to contribute, here is the link:

http://www.aag.org/katrina/

If you are an experienced GIS user, GISCorps, a volunteer organization under the auspices of URISA, coordinates short term volunteer GIS services for many things, including humanitarian relief, and need EXPERIENCED GIS volunteers for Hurrican Katrina relief efforts. If you think you might be able to help, information and forms are available at the GISCorps website

http://www.giscorps.org/

There are numerous blogs, websites, and other Internet resources on Hurrican Katrina, so I can only mention a couple. The devastation is unbelievable, and our thoughts are certainly with all the people who are trying to cope with the aftermath, but it underscores how important an understanding of geography and our environment is, as has been pointed out many times in the case of New Orleans. Here are a couple of links to some of the many resources out there, including uses of Google Earth to provide locational information on levee breaches.

ESRI is providing GIS assistance for organizations, with information available at http://www.esri.com/hurricanehelp

Here are a couple of links to uses of Google Earth to map aspects of the disaster

(via The Map Room) http://www.kathryncramer.com/kathryn_cramer/2005/08/new_orleans_lev.html

These are still images of Google Earth output:
http://www.flickr.com/photos/gisuser/

And finally, if you’d like to help the Red Cross National Disaster Relief Fund:
http://www.redcross.org/