Contour Design has introduced its Showcase nano v3 and Showcase touch cases for the iPod nano (with video) and iPod touch. The cases are made from shock absorbing rubber and clear polycarbonate, offering dual-layer protection. Other features include a hinged door, a hinged Dock Connector port protector, a removable, multi-position belt clip, a press-through hold switch cover on the touch model, and a play-through Click Wheel protector on the nano…