Mili has debuted its new Power Pack battery case for the iPhone 4. Sporting a slide-in design, the Power Pack features an integrated 3000mAh lithium polymer battery, which the company claims is good for up to 11.25 additional hours of talk time or Internet use over 3G, up to 87.5 hours of audio playback, or up to 22.5 hours of extended video playback. Other features include a built-in stand that works in both vertical and horizontal orientation, open…
