It's apparently iPhone 4 accessory day with another new battery power case coming to market. This case is from a company called PADACS and is called the PowerCase. The company doesn't specify if the case is for the Verizon or AT&T iPhone 4, but a look at the design appears it could work for both.
The case promises to double the run time for the iPhone 4 and comes in two versions. The PD-126-16 version sells for $49.95 and has a 1600mAh battery inside. The PD-126-22 version has a 2200mAh battery inside and sells for $59.95. The smaller battery version weighs in at 0.15lbs and the larger battery version is 0.19 pounds.
The company clams that you can get up to seven extra hours of talk time on a 3G network with the case. PADACS ships the cases with an iPhone 4 screen protector as well. You can order either version of the case today.