If you want to have some choices in charities to help out the Katrina victims, look at Glenn's post here. You'd be amazed at the sheer number of charities available.
I just spent a large amount of cash upgrading the house I've purchased. Funds are low, and I won't see a paycheck until the end of September. I usually don't donate to relief efforts. But I'm going to this time.
I have a friend from New Orleans.