2 excellent Christian relief organizations:
Southern Baptist's NAMB: http://www.namb.net/
Samaritan's Purse: http://www.samaritanspurse.org/
Another very effective Christian relief organization (with which I'm connected and can vouch for absolute honesty and accountability):
http://www.raphainternational.org/
They concentrate on medical relief but are also doing food, etc. to NO, as well as bio suits and decontamination supplies. Rapha did extensive work after the tsunami and had officials Thailand within hours after the big waves hit.
And an affiliate is opening a shelter in Arlington today. I spent part of yesterday at the food pantry, and they're loading more trucks as I type.