New Orleans is not just in bad shape; it's devastated. Harrison, Mississippi was the worst-hit, though (55 or more dead). [UPDATE: Or so it was when this was written; Harrison County now has deaths in excess of 100. With deaths from flooding and the like NOLA has certainly surpassed this; how much more is unclear, since currently there is more of a focus, and rightly so, on finding living people than counting dead ones.]
Wikipedia is being updated quite well, and is another place to get updates.
Here's a list of charitable organizations for those wanting to assist victims of Katrina. (HT: Rebecca Writes)
On looting in New Orleans: I notice that some people are justifying their actions in terms of survival (e.g., feeding their family). If (a) they are truly in desperate need; (b) they take only what they need; (c) do not act violently; then morally they are right. It's common use; whatever it may be called legally, it is morally not theft. The idea behind common use is that while ownership may be private, thus giving the owner powers of stewardship to adjudicate conflicts and make decisions about how the property is to be used, the use itself is common. Human beings hold all things in common, not by ownership, but by use consistent with common good (the good each person has by virtue of living in society with other persons). Under ordinary circumstances, one must defer to the stewardship powers of the owner, in order to preserve the order of society and use the property in a way consistent with common good; but these stewardship powers do not remove common use, but merely involve what is required to maintain common use in an orderly way in ordinary circumstances. (The same principle is what makes it legitimate for authorized agents of government to commandeer property when genuine need arises; early reports of 'martial law' were actually distorted reports of state-of-emergency powers to commandeer property and compel evacuations at need. Similarly, people in desperate need who are, in fact, merely commandeering necessities, are acting with complete moral authority. Of course, people who commandeer in need should be aware that legally they may still be held accountable later for any injury to others, including the people from whom they are taking, and their moral responsibility is to accept that, assuming that the means of holding them accountable is just.) Of course, most looters don't meet all of the above criteria; they are violent, or take things they do not desperately need.
UPDATE: Well, what do you know; Wal-Mart seems to get the principle, at least for this sort of situation. And, it seems, ol' WMT has a rather impressive emergency relief system, and has apparently done this before.