If you own an iPhone 3G and are looking to pick up some extended battery life and are tired of trying to fine tune settings to get a few more minutes you need the all new Mophie Juice Pack Air.  This hard case is also an external battery that can provide your iPhone with almost twice the battery life.  It is Apple certified, has an on off switch to tell the iPhone to run off the case or it’s own battery, pass-though USB charging and sync, and has an integrated 4 LED display so you know how much Juice you have left.  I just ordered one for my iPhone since I use it on my commute and the battery doesn’t last as log as I would like.  Hell for under $80 you can’t go wrong with this hard case.