I just posted a note about this over at Jo Leigh's blog, but I'll repeat it here for those who want to help out the victims of Hurricane Katrina.
Donating blood is one of the most important things you can do in the aftermath of a disaster. There are likely to be a huge number of casualties from Katrina, and the first thing hospitals always run out of is blood.
Routine blood donation drives in the southern part of the U.S. will also be badly disrupted by this storm -- we saw this last year after the four hurricanes that hit our state -- and medical facilities outside the disaster areas who send their inventory to relief areas will need help replacing their stock.
A pint of blood costs nothing but maybe twenty minutes of your time to donate, and it can actually save someone's life. If you're willing and able to donate, please do.