Steve Olson, a science writer, does an excellent job of explaining, in layman’s terms, what a scientific theory is and why the people pushing the mysticism known as "intelligent" design don’t even come close to the same concept.
When scientists speak of the theory of gravitation, cell theory or evolutionary theory, they are talking about scientific concepts that have been so thoroughly tested that they are very unlikely to change. Theories are the results of decades or centuries of scientific effort. They draw on many interconnected observations and ideas. They are the end products of science, not stages on the way to the truth.
It would be nice if the school board members and politicians who are pushing for creationist crap to be given equal footing with evolutionary concepts in high school classrooms would read this article. It would be nice, but I doubt it would help.
There is no science – indeed no intelligence – behind "intelligent" design. As Olson points out "creationist organizations such as the Discovery Institute in Seattle are spending most of their money on public relations rather than research". Marketing the hypothesis is the whole point.