Here is some useful info on where to donate, how to get involved, and how to get in touch with people:
The American Institute of Philanthropy
Charity Watch announces its top-rated charities currently offering relief services to the victims of Hurricanes Katrina that have experience in the area:
American Red Cross (A-)
1-800-HELP-NOW
America's Second Harvest (B+)
1-800-771-2303
Church World Service (A-)
1-800-297-1516
Salvation Army (A)
1-800-725-2769
MAZON: A Jewish Response to Hunger (A+)
310-442-0020
Some other useful info:
Habitat for Humanity is taking donations and volunteers to help rebuild.
Offers for housing on Craig's List:
http://neworleans.craigslist.org/hhh/
CNN is taking emails to help people get in contact and report if they are ok to loved ones:
http://www.cnn.com/SPECIALS/2005/hurricanes/feedback/
Forum on Nola.com is connecting people too:
http://www.nola.com/weblogs/nola/index.ssf?/mtlogs/nola_nolaview/archives/2005_08.html#075477