The hard plastic shells we've seen for the iPad 2 can be split into one of two categories: either they extend all the way to the top and bottom edges with cutouts for the buttons and ports, or they leave wide openings along both edges, exposing parts of the tablet unnecessarily. Crystal Cover Set for iPad 2 ($30) from Simplism bucks the trend and falls right in the middle. It runs all the way to the bottom edge, with a cutout for the Dock Connector…