Morphie's Juice Pack Air for the iPhone 4 combines the protection of a hard-shell case with the added life of an external battery. The case doubles as an acoustic coupler, redirecting and enhancing your phone's internal speakers; an included USB cables lets you sync your phone without removing it from the case. The Juice Pack Air's 1500mAh battery isn't the highest-capacity we've seen, especially in a case/battery combo, but you can get the case for either your AT&T or Verizon iPhone, and get it in your choice of three colors (just basic black for the vPhone version, sorry!).
Need more amperage and/or don't need another case? Move up to the Juice Pack Powerstation, which more than doubles the Air's battery capacity to 3600 mAh (and promises recharge up to four times faster than other USB battery packs). And since it's an external USB battery, it'll power up a variety of devices, Apple's or otherwise.
Check out our hands-on reviews of both units below: