The new Kensington iPhone 4 battery case offers a straightforward design, color options, and a slot plus card that function as a stand.
Kensington PowerGuard Battery Case
The first thing I noticed when I picked up the case was how lightweight it is compared to similar cases I used with my iPhone 3G and 3GS. It is also very compact, about ⅛ inch thicker than any regular case I have on hand for comparison and less than ½ inch longer than those cases. The package includes a card (about the size of a credit card) that functions as a stand, the power cable and a manual.
Available colors are black, white, and blue and the MSRP is US$59.99. I found it on-line at prices ranging from US$40.00 to US$64.00.
The manufacturer claims that this unit adds four hours of extra talk, five hours of videos, or two hours of music with the caveat that as the unit ages, there will be a decrease in productivity.