A small pokeball-shaped holder for DS and 3DS game carts that clips onto a belt. Paint the pokeball parts, glue them together, and slide the cart inside, then push the ball into the clip to conceal the card entirely.
This is a first revision and will likely change, buy at your own risk. Designed around the actual 3DS cart dimensions but not yet tested.
Feedback is very welcome!
Pokemon is owned by Nintendo and Game Freak.