Ya, GameGear cases do the job, but the games need to be rotated and it looks silly. Any other ideas besides this or modding NDS cases?

once you trim a little off the plastic thing inside, its a very snug fit. sideways makes more sense, because now it opens like a book. there is also a place for some art if you take the time to trim it to the right size. i’m working on a case project using them and its turning out great. they are smaller than anything else, fit the game exactly, and provide room for art on the inside (where it won’t rub off).