Skech has recently released a bevy of cases for the iPhone 4 that fall in to two different categories: first are the polycarbonate Hard Rubber ($TBD) and Rise ($TBD) cases, followed by the leather and faux-leather Custom Jacket ($TBD) and Custom Jacket Flip ($TBD). Hard Rubber and Rise are both plastic slider cases with black felt-padded interiors; the Hard Rubber models are all solid colors, while the Rise cases have gradients that darken as they…