All of these where made by reversing an old 55mm lens. The older shots where taken with my Casio QV4000 and then the 55mm was screwed backwards on a lens adapter. Now, on the Eos 300D, I screw it reversed on my standard EF 50mm. Reversing a 50mm on another one makes for a very cheap Xtreme-macro lens!
Looks like you've made excellent use of your little setup. It doesn't take that much to have tons of fun exploring the possibilities. A little bit of equipment and a lot of heart can go a long, long way. Tom