Princess Debut, features a lovely activity that is probably designed for little girls, but is kind of fun anyway. In keeping with the theme of not actually being a princess, you can design a DS cover out of fake rhinestones and then print it out! If you aren't feeling creative, there's even a template available to color in.
Ideally, you'd affix this to the system by slipping it inside a transparent cover, but you'd probably be okay using just a little tape. Alternately, you could just mess with the editor for fun. But then how would your DS get any more princess-like?
[Via GAME Watch]