When a non-scientist with an agenda uses the word. Or when a non-scientist who slept through biology classes uses it. It's very popular in Kansas these days.
The word "theory" means something different to a scientist than it does to a non-scientist, especially a fundamentalist Christian, apparently. Theory does not mean "guess" or "estimate" or "extrapolation." It describes the result of a scientific process; it is not itself a process. The best explanation is this one, presented in blog called Balloon-Juice (out of Texas, believe it or not) run by John Cole. You can read the whole entry here.
A scientific theory or law represents an hypothesis, or a group of related hypotheses, which has been confirmed through repeated experimental tests. Theories in physics are often formulated in terms of a few concepts and equations, which are identified with "laws of nature," suggesting their universal applicability. Accepted scientific theories and laws become part of our understanding of the universe and the basis for exploring less well-understood areas of knowledge. Theories are not easily discarded; new discoveries are first assumed to fit into the existing theoretical framework. It is only when, after repeated experimental tests, the new phenomenon cannot be accommodated that scientists seriously question the theory and attempt to modify it. The validity that we attach to scientific theories as representing realities of the physical world is to be contrasted with the facile invalidation implied by the expression, "It's only a theory." For example, it is unlikely that a person will step off a tall building on the assumption that they will not fall, because "Gravity is only a theory."Note the part about "confirmed by repeated experimental tests." The best source for information on the Kansas trial is Panda's Thumb posted by Tom Matzke. And, the Moonies are involved. Also try Red State Rabble. It has an audio link. The wrap-up is from the Kansas City Star.
The hearings did not go well, and my belief that the science community was wrong to boycott it, was misguided. They were right. Now the infighting in the ID crowd has begun, and as usual Panda's Thumb is your best source.
William Saletan, in Slate, writes a defense of Intelligent Design, claiming that it shows that the anti-evolutionists have evolved from those opposing the teaching of evolution, to those saying, well, maybe there was a Creator who pushed this along. Saletan's problem, however, is that a lot of people believe that (maybe even me), but that, as one rabbi said, is religion not science and doesn't belong in a science classroom.
And if you really want to throw up: here.