Though the iPhone 3G may not be long for this world, Mophie's Juice Pack Air ($80) may continue to be of interest to the millions of users who are locked into using the battery-draining 3G even after Apple replaces it. Designed specifically for this iPhone model, Air combines a thin 1200mAh battery pack and a glossy white or black plastic case that offers top, side, bottom, and back coverage, though nothing for the 3G's screen; thanks to its comparatively…
