I just got back from my daughter's science fair at school. There was a sheep heart, and some worms, and solar panels, and catapults - one of my drawing students used one to shoot a piece of cereal into my shirt that I think is still there. Anyway, it was cool. I know there's a lot of concern about getting kids interested in science, but I think anything that's applied to the real world is inherently interesting to a kid. Also, anything that's in story form is inherently interesting to a kid. And, as was clear from the cookie tasting experiment, anything that involves eating cookies is inherently interesting to a kid.
Anyway, it was great fun. And as an offshoot to my earlier rant about art here, I think the same goes for science - showing how everything in your world came from invention, and experimentation, and knowledge of the properties of materials and DNA and mechanics and all of it, is very much like showing how everything is designed. It's all the result of creative thinking and investigation. I think kids get that - if it's shown to them in the real world. Kids are sort of the ultimate reverse engineers - they see something and want to know how it got that way. And it helps to have cookies.