OtterBox has released its new Defender Case for the iPhone 3G. The Defender uses three separate pieces to protect the iPhone: a clear polycarbonate screen protector offering chemical and abrasion protection, a hard polycarbonate “skeleton” that surrounds the device, and silicone skin that wraps around the skeleton, absorbing bumps and shock. The OtterBox iPhone 3G Defender Case also includes a ClipStand holster and is available now in…