Idea for Ecology Pyramids foldable! (Okay, I know, this particular pic is for a food chain/web, and, yes it's got some gross errors, but I like the overall idea for the foldable.) For each side: Energy Pyramid, Numbers Pyramid, & Biomass Pyramid! I like it! You could also do something like food "webs" (trophic levels) for 3 different biomes! Compare and contrast!
Also on these boards
Awesome idea from Earth Mama's World: Food Chain game out of styrofoam cups! Just glue images on to your cups and write the name of the organism on the rim. Mix them up, have kids put them in order, and stack them!