Lots of iPhone users can tell you that the screen on the smartphone is very fragile. Drop it one time onto a hard surface and odds are you will be looking for a replacement screen.
With the new iPhone 4 having glass on the back and front a sturdy case is in order. A new case from Ballistic Cases has surfaced called the Ballistic HC specifically for the iPhone 4 smartphone.
The case has four layers of protection with an inner rubber layer, a rigid internal structure covered by more rubber, and a removable outer silicone layer. The case will sell for right at $50 when it launches soon.