Tim and Dave (and everyone else), You might want to make some of these projects with your children. With just one component, you can make polyhedra, Wieringa roofs (raised Penrose tilings) and quasicrystals amongst other things: http://cp4space.wordpress.com/2012/09/01/activities-with-golden-rhombi/ Everything you create in this way is compatible with everything else. Rhombic triacontahedra and hexecontahedra fit snugly inside the 'valleys' of a Wieringa roof. Sincerely, Adam P. Goucher http://cp4space.wordpress.com/