Although I believe in evolution, I read somewhere that the appendix makes a minor contribution to the immune system. Thats not evidence for Creationism in my opinion, and its not so important that the appendix can't be removed, but apparently a lot of white blood cells gather in that part of the body.
Also, there are a lot of introns in our DNA which don't code for anything, making them useless to us. There are even broken genes, such as the one that would allow us to synthesize our own Vitamin C, but its broken in all primates, including humans. I see no reason for those genes to exist.
EDIT: The reason I don't think the appendix having a function is evidence for Creationism is because other animals have use for it. Many herbivorous animals have a much more developed appendix than we do, and they use it to digest plant matter that would be indigestible without an appendix.
[This message has been edited by Gary, 03-18-2004]