I hope someone else hasn't already posted this...I found a group that is knitting some facecloths and sending soap as part of the relief effort. http://groups.yahoo.com/group/clothsforkatrina/
Since sugar and cream is usually $1.00 at Hobby Lobby and soap can be found pretty inexpensively it is something almost anyone can do.
I know its not as grand a gesture as money...but it is something that most of us can afford. It seems like a handknitted, "made with love" kind of item would be much appreciated.
Oh and if you know of any fun dishcloth patterns, please let me know. I know there is someone on here who does a lot of them but I can't come up with the name right now.