As part of its new power accessory line for Apple's iOS devices, Mipow has released two battery cases for the iPhone 4: the oddly-named Clone ($69) and Maca Air Color ($79). The cases are somewhat similar in form but vary in finish, size, and capacity. Clone holds a 1500mAh battery in its matte plastic rear compartment. Unlike many such cases, they battery can be removed and swapped -- the company even sells a spare battery and charger kit. Beneath…
