As an improved version of its well-known Slider Case, Incase's Pro Slider Case for iPhone 4 ($40) looks pretty much the same but has a few key differences. It still splits in two, with a slide-off portion at the bottom serving as the opening for inserting and removing the device. Instead of a totally plastic body, though, it has hard rubber along the edges to provide some shock absorbency. There are also soft pads lining the inside to help protect…
