Photojojo is selling an 8x telephoto lens for the iPhone that attaches to your device via case that the lens twists onto.
When you aren’t using the lens you can just leave your nifty new case on and slip the lens in your pocket (try that with a 500mm Sigma). It’s a lens and case in one, always at the ready.
If you’re looking for a more composed shot, you can use the collapsible table tripod (included) to steady and focus your photos. It’ll come super handy when you’re shooting in low-light.
Each telephoto lens comes with a phone case, a mini-tripod and a cleaning cloth and costs $35.