The Australian Red Cross will be accepting online donations to help the victims of Hurricane Katrina as as soon as they have clearance to issue tax deductible receipts. If getting a tax deduction isn't your first concern you can make a donation to the American Red Cross.
Other organisations also have appeals. GuideStar, a US guide to non-profits, has some general advice about choosing a charity. For bloggers the Truth Laid Bear has some advice on how you can help with fundraising.
Australians concerned about family and friends in the region can register their details with the Department of Foreign Affairs and Trade on the special hotline number 1800 00 22 14.
At Barista David Tiley is posting a steady stream of links, news and pictures.
If you're feeling generous, make sure you don't forget about the Red Cross' work in Western Africa. The charity is currently seeking $18 million to assist international efforts to avert widespread food shortages in the Sahel region of West Africa. According to PBS:
Starvation threatens 3 million people in Niger and millions more in other impoverished African countries, but a lackluster international response has failed to provide the needed emergency relief.
Oxfam also have an appeal. Check their web site for more links and information. It would be real tragedy if Katrina sucked up all the international donations just because it got the most TV coverage.

Thx for that Don. I'd better give some money to Africa, though I'll give it through "M
I'd go long on Africa, Nicholas. The US will raise many many millions in pretty short order - the trouble is applying it on the scene - they don't lack money - they lack access etc
Yep - hence I'm hoping MSF will do the best that's possible with the money.