I loved this game a lot, and wrote down a whole lot of different codes for various combinations of things. I went through the game just far enough to get all kinds of cool stuff, but didn't go through to start fighting bosses and whatnot. I wrote all this down on pieces of paper, then gave away the entire lot of stuff.
If I had only kept the codes then I could just buy back another set of stuff, or use emulators or the like. Maybe when I get a Nintendo DS again I'll be able to buy this game again (see atlus.com) and I'll just play it over and over to get some good codes again.