Looks like the iPhone 4 is finally getting the Mophie Juice Pack Air which provides a bit of protection (in the form of a case) and an extra 1,500mAh lithium polymer battery built-in. The extra battery on the Mophie Juice Pack Air will give you and extra 6 hours of talk time on 3G and 12 hours on 2G. In addition, your music listening time now has an extra 36 hours! Yours for about $80 here.