The Red Cross is reporting that donations from individuals and institutions are flowing in. Here is a page from FEMA with tips and guidelines for donations.
Adventist Development & Relief Agency (ADRA) has set up a hurricane relief fund here.
Church World Service has a donation page up.
For you misplaced Anglicans, there is Episcopal Relief & Development.
America's Second Harvest also has a donation page.
Lutheran World Relief is here.
United Jewish Charities has their page here.
Islamic Circle of North America is here.
For us Godless heathens, I suppose there's Morgan Freeman's charity auction at Charity Folks, especially since they're listing some big ticket items. Maybe the auction winners will donate the prizes, too.
More as I find them.