Otterbox has introduced its OtterBox for iPhone, the company’s first “semi-rugged” iPod case. The OtterBox for iPhone combines a hard polycarbonate shell with a patented polycarbonate membrane to protect the device’s screen while allowing for complete usability, and an outer silicone skin to add protection from drops and bumps. The resulting case is water-resistant, and features three Donaldson Acoustic Vents for the front…