Those multifunctional gadgets are always welcome such as the following iPhone case called MiLi Power Skin.
This multifunctional iPhone case is manufactured by HALI-POWER, a China-based manufacturer. MiLi Power Skin features ultra slim design, but the material used by the iPhone case doesn’t described on its product page. Moreover, it integrates a 1200mAh rechargeable battery that can be charged through the built-in USB port.
MiLi Power Skin can be fit for iPhone 3G/3GS, and is available in various colors. However, there is no further word on the release date and the price at iPhoneMili. Well, stay tuned.
Update: Now the MiLi Power Skin iPhone battery case has been available. Through Google Shopping find the most suitable one.