The IFF also does some wonderful workshops on "modular origami," which is building shapes out of, typically, cubes made of business cards. The basic directions

The IFF also does some wonderful workshops on "modular origami," which is building shapes out of, typically, cubes made of business cards. The basic directions are pretty simple (http://theiff.org/images/menger/sponge%20cube%20instructions.pdf http://theiff.org/images/menger/sponge%20cube%20instructions...), and you can make the "level 1" Menger cube shown there in a couple of hours. It's a fun diversion in restaurants to make a cube or two from postcards or business cards that they might have laying around. The IFF sponsored a very large Menger sponge (http://theiff.org/oexhibits/menger02.html http://theiff.org/oexhibits/menger02.html), which was shown around various places in LA, including a library at USC. Finally, they have branched out in other ways, using iterated construction rules to make crocheted surfaces that expand everywhere ("hyperbolic geometry") to mimic coral or other natural shapes (http://theiff.org/exhibits/iff-e5.html http://theiff.org/exhibits/iff-e5.html). There is one of these at the Museum of Math in NYC (http://momath.org http://momath.org), and they have shown them internationally (http://crochetcoralreef.org/preorder-crochet-coral-reef-book.html http://crochetcoralreef.org/preorder-crochet-coral-reef-book...).