Beyond what the already awesome in-built camera has to offer, we have an add-on lens called the Photojojo iPhone lens. Armed with rotating lens adjustments, this awesome pack offers tiny wide-angle, fisheye and telephone lens. All this, made with optical-quality glass and aluminum. The camera achieves steadiness with the help of a couple of tripod mounts. So you can shoot panorama pictures with the 0.7x wide angle lens, 0.33x fisheye lens and 1.5x telephone lens.

The camera lens packs will cost you $249 and will find compatibility in the iPhone 4 and 4S.
Photojojo