The theory of evolution has been subjected to scientific debate for well over a century and currently in 2011, it is the best theory scientifically available. Creationism is a concept that is solely derived from religious beliefs and has not undergone the kind of scientific scrutiny and debate needed to be considered a truly scientific premise.
Until the concept of Creationism can be elevated to the same scientific status of evolution based on purely scientific methods and premises, it should not be allowed to be taught in any public schools that receive public money.
In summary, within the scientific method, a concept and a theory are two very different things, and a "scientific concept" weighted on religious belief over scientific methods has no place in United States public schools.