Incipio's dermaShot ($20) is a reworking of its basic, budget silicone rubber case for past iPhones, designed of course to match the curves of the iPhone 4. Six colors are available, each single-toned with a matte finish, using cut-outs to expose the iPhone's cameras, headphone port, microphones, speakers and screen. Button protectors are integrated for the top and side controls. As the first case we've seen to include its own screen film protector,…