I do a fairly cool activity with my middle schoolers, as we introduce polyhedrons (not as detailed as your students, but still dealing with prisms and pyramids/cones). It’d decidedly NOT technological, unless you consider a circle of paper to be high-tech. But with about a 7″ diameter circle of paper, you can fold it and discuss various polygons along the way, and wind up folding it to create a truncated tetrahedron. And then with a whole class of those (assuming that you have at least 20 students in the class), you can tape them all together and create an icosahedron. It’s pretty tactile activity, and it sure doesn’t lend itself to using a video projector, but for the most part my students always love it. And it makes a good model to keep pointing back at during subsequent lessons.

Yeah, here you go – it starts on page 26 of this
PDF (actually, pages 26-30). Sorry, if I were at school with full Acrobat I could extract those specific pages for you. It even comes with a sample circle that you can print out (but I suspect that your Mac will allow you to draw circles too ;)

Errata: I just realized that in my original post I said “polyhedrons” when I should have said “polyhedra.” My bad.

Note: With this quasi-origami project, I’ve found that my ADD/ADHD students pay awesome attention, although it can turn into an obsession – one student apparently went home, proceeded to cut out and fold 20 circles for himself, and taped them into an icosahedron. He then hackeyed it around like a soccer ball until it fell apart, so he proceeded to make another 20 circles and fold them all again!

I’d say that the toughest part is cutting out the darned circle. While it’s not required that it be a perfectly smooth circle, it sure makes things work better. At our school, students are allowed to possess scissors, which made that task go much faster. If I’d had to cut them all out myself for all of my sections, I would have not been terribly happy.