One of the main features of the Nintendo DSi when it was released was the addition of two cameras. Although it wasn't its strongest point, its a great addition that (we hope) will prove useful for future apps and games. And it looks like Nyko is foreseeing that future too. Just recently they introduced the Zoom Case.
In a nutshell its a DSi case with a camera lens. An 8x zoom camera lens. I kid you not. If you're one of those whiners about how crappy the DSi camera is, then I would kindly point you to this product. The lens is detachable, of course, and the case is not kidding around either. What's more, it does not require batteries.