Check out this cool invisibleShield for your iPhone/iPhone 3G/iPod Touch, basically it makes your iPhone scratch-proof with a layer of plastic. (yes, or polyurethane film for you chem-geeks)
ZAGG’s invisibleSHIELD™ is a thin polyurethane film originally created for the military to protect the leading edge of helicopter blades. What’s unique about this military-grade, patented film is how tough it is – it doesn’t scratch. What makes ZAGG’s exclusive invisibleSHIELD™ so strong, flexible and scratch-proof? Its Nano-Memory technology™. With this technology, it also allows it to curve and contour around an entire device (not just the screen) and adhere to the device unless you want to remove it (without leaving adhesive).