Glenn Reynolds at Instapundit has complete coverage of where to offer assistance to victims of Katrina.
N.Z. Bear has a community set up, and Terry Teachout has comprehensive links to up-to-the-minute reporting.
As has been remarked by Austin Bay, the only America that's prepared to help out with this one is America herself. And that would be us.
Technorati tags: flood aid, Hurricane Katrina