Science should be taught in school. The data, how it was achieved, what has been discovered--these are the backbone of science. But science cannot mean much without interpretations as to meaning. Evolution is the reigning paradigm governing those interpretations at the moment, and in that light should certainly be taught. It is not a fact apart from simple speciation, however, and should not be taught as such. I personally don't mind if creationism is not taught. I do think, however, that challenges to the evolution interpretation should be discussed, and the idea of options to that interpretation be discussed. But as for actually injecting a religious viewpoint into the discussion in terms of the Bible, the Koran, the Vedas, or any other religious work--that might be a good project for a term paper to compare different ideas, but it is not a good idea for science classroom study. Since evolution itself is an idea that is quite pervasive, however, it certainly should be part of the curriculum, but it should not be treated as some sort of icon immune from challenge or disagreement. To do so is to disallow students to think their own way through data and possible meanings. We need scientists-in-training, not robots.
Creationism has a place in education, but only in the study of religion and culture. Science classes need to focus on tested theories and hypotheses instead of religious beliefs. There is no place for creationism in the hard sciences and trying to put it in the curriculum undermines the purpose of these classes.
Since the basis of science is that hypotheses and theories are subject to experimentation and refutation based on evidence, creationism cannot be taught as true science. Creationism cannot be proven by an experiment; rather, it is an untestable idea or philosophy rather than true science. It should be taught that it is a belief system based on untestable axioms, rather than a scientific theory.
Creationism is a religious belief. There is no basis in science that this even happened. Granted, no scientist knows definitively for sure how Earth was created, the evidence toward The Big Bang Theory and evolution exists. Creationism should only be taught in science classes as a contrasting belief to the evidence of science.
Besides the fact that there is not sufficient scientific evidence to support a belief in creationism, it is not only inappropriate but a violation of the constitution to teach it as it is a religious based belief. The constitution strictly forbids the integration of church and state. So teaching a creation theory based on the belief in a higher being should not be allowed.