Creationism isn't science. Pure and simple. It's not taught in accredited colleges, isn't written about in peer-reviewed journals, isn't researched in the biology labs of premier colleges.
Sure, some people are big on it. They even have their own journals. That's their deal. There's perpetual motion people too.
Public school is, to a large extent, college prep. You're being taught, in addition to the basics any citizen should know, what your professors in college expect you to know going into their introductory courses.
So, first off, Creationism shouldn't be taught in science class. It's not what biologists consider science. It's not what courts consider science. If you don't like it, yank your kid. He can take another class instead. There are plenty.
Don't taint my child's biology education because of your religious beliefs.