Zeki Ozek wants to complement your current camera with an iPhone and eliminate SD cards, clunky factory-installed interfaces and whatever else attaching Apple's smartphone to the back of your rig might accomplish.
He proposes we do it with iCam, a camera with a dock in the back that syncs up with an iPhone courtesy the 22 pin connector. The concept won a Red Dot Design Concept award this year, based on the design's incredibly broad potential. Strapping a powerful, portable touchscreen computer to the back of a custom-built camera can do that for you. Plus, wireless connectivity. Cannot understimate the convenience of that.
Cameras will be wireless, hyper-connected, uber-customizable devices in the near future anyway, but there's no denying the iPhone's potential in this early, specific case.