When it comes to iPhone cases, people usually want them to do two main things: protect their prized phone and be comfortable to use (and possibly charge the phone like the JuiceTank or the Sandberg BatteryCase). If you're willing to sacrifice comfort for more durability however, Japanese company, Marudai Corp. has got the product for you. Its newest case for the iPhone 4 is so heavily armored that the company claims it can stop a direct hit from a .50 caliber bullet, while keeping your smartphone intact.
The armored case features an inch of solid steel embedded in the back, which is what gives the phone cover its bulletproof ability. To attach the case, the phone has to literally be bolted in using an Allen wrench. Marudai also claim that a bullet hitting one of the bolts will still leave your iPhone undamaged. But while the back of the case is solidly protected, the front screen is still completely uncovered so the phone's touchscreen can still be used.
Of course, the hefty case does come with quite a few disadvantages. For one, the case raises the weight of the iPhone 4 from half a pound to about 4.5 pounds (2.1 kg) and the thickness from half an inch to about 1.5 inches (39.6 mm). That doesn't exactly make for a comfortable case that can fit easily in your pocket (though on the plus side, you could get a good workout from power walking with it in your hand). Another disadvantage is the thick armor plating requires a separate lens for the camera, which restricts its viewpoint to a smaller circle and makes all your pictures look like they were shot through a peephole.
Aside from all that, there's one more, much larger disadvantage: the price. Muradai is selling their bulletproof case for 52,500 yen (US$650), although that does include free shipping, a spare lens, and a commemorative dummy bullet. Considering that's almost twice as much as the cost of a brand new iPhone 4 though, it might be easier to just get a good warranty and back up your data regularly.
Source: Marudai Corp