I'm open to the possibility that we did not evolve.
I think the human being an alien genetic engineering experiment is an interesting theory. I have to say that I do hope that the aliens do not come back to "extinct" us, as some people theorize. (Yes, I have been to a Star Trek convention). As far as "Creationism" by a single, omnipotent god - I am less inclined to believe this, but not completely closed to the idea.
I am interested in the differences between us and the apes as well - if you know any good links, please post them:-)