I just realized a more important point. If a child asks a teacher about ID, wouldn't it be reasonable for a teacher to simply ask what is the theory of ID and state they have never heard of such a thing?
Actually, I don't think so. I understand your point, but I think a quick and dirty history of theories help understand why the theory was composed, and why the old beliefs were discarded. "Centuries ago, people used to think that the sun revolved around the earth, geocentrism wasn't seriously considered until the 15th Century when..."
The same thing was done with ToE when I was taught it. "Before Darwin, most scientists believed that life was created by God. The fossils they found led them to believe that life had changed on earth over time, but it was assumed that the appearance of different 'types' in the fossil record were indicitave of seperate creation events and several catastrophes, Noah's being the last. Whilst this was scientifically problematic, they argued that there was such complex design in life that it must be true...an argument known as 'argument from design', or teleology. Darwin paved the way that not only explained how the diversity came about but the mechanism of design, and the fossil record. Scientists quickly saw how simple but powerful...."
I think that showing that ID is actually an old, largely abandoned hypothesis would be better than sticking bananas in kid's ears and singing. But that's just my opinion.