Leave it to the Japanese to come up with one of the most interesting iPhone cases thus far. Cut from two separate sheets of aircraft grade duralumin, the Quattro iPhone case features a lens mount that allows for interchangeable external lenses such as fisheye, wide angle and macro. To top things off the backing is made up of calf leather. Now available from Factron
for a price of 19,600 yen (approximately $200 USD) plus more for each lens. A little pricey, but looks like a lot of fun!
More images of the Factron Quattro iPhone 3G Case after the jump.