Between its 8MP sensor and internet connectivity, the iPhone 4S is one of the best point-and-shoot cameras around. It can download thousands of photo-editing apps and upload images to a number of services.

But the lack of interchangeable lenses, a weak flash, and other missing features means that the iPhone won’t be replacing your DSLR anytime soon. Unless, of course, you had something like the 3RDi camera kit…

The 3RDi Kit, from Knight Vision Studio, is a full-on camera kit for the iPhone 4 and 4S. It includes a Wide-angle lens, a Fisheye lens, a Polarizer filter, an ND filter, a Lens Grip, and a case for your handset.

All of these things come together to dramatically enhance your iPhone’s picture-taking abilities. The Wide-angle lens adds depth to your photos, the Polarizer filter deepens colors, and the case holds it all together. As a bonus, the Lens grip has a built-in cold shoe mount, allowing you to connect an external flash or other accessory.

As you might have guessed by now, the 3RDi Kit is currently only available via Kickstarter. To get one, you’d have to pledge $135 or more, and hope that the team hits its lofty goal of $150,000 by August 19th.

And for those of you who want to improve their iPhone picture-taking skills without ponying up $130, be sure to check out our ongoing iPhoneography series. It’s full of tips and tricks for getting the most out of your iPhone pics, and is written by a real photographer.

What do you think of the 3RDi kit? Would you buy one?