Mophie Juice Pack Pro
It used to be that if you wanted a case with extended battery life and ruggedized protection, you were out of luck. The two were separate cases, and, never the twain shall meet - until now. Mophie, known mostly for their extended battery pack cases, designed their latest high capacity battery in a shell that also carries Department of Defense environmental certifications. The case features multiple layers of protection and seals the iPhone's ports against water (though it's not waterproof), sand, dust, shock, and vibration. The battery is rated at 2,500 mAh, which provides 150 percent more power than a stock iPhone 4 or 4S. However, if you're looking for something svelte, this case is not for you. It adds at least another pound to the phone in addition to bulk. However, if you're on the go to areas that may not be the most friendly to iPhones for extended periods of time, the Juice Pack Pro should be considered.