I am an avid iPhone 3G user, but my chief complaint about the device is the battery lifetime. All of the extra hardware that makes the iPhone great (GPS, WiFi, 3G GSM, accelerometer, digital compass, etc.) drain the non-replaceable battery within a day of charging, with moderate use. Not surprisingly, a slew of add-on products from manufacturers such as Dexim have hit the market to append the poor battery performance of the iPhone. The Dexim P-Flip offers an extended battery in the form of a foldable dock.