This is my first post so please go easy on me. I am a new iPhone 3G owner and I have concerns that my battery won't always last a full day if I spend a lot of time in 3G mode, watching movies, or playing 3D games. As a backup I purchased the Lenmar Powerport last week and thought that I'd share my review of the device: Manufacturers Product Description: Lenmar Universal Powerport Kit: AC & DC USB Power Adapter [*]Universal USB PowerPort will charge or supplement iPods, Sony PSP, cell phones and PDA's or any USB Powered or chargeable device - Black Color [*]Includes Ultra Compact 100-240V AC - USB and Automotive 12VDC - USB Power Adapters that can Power / Recharge your device and the PowerPort [*]Can recharge your device up to 4-5 times on a single charge. Includes PowerPort Battery, 3 ft. charging cable with tips for iPod, PSP, Treo, Motorola RAZR/KRZR and other mini USB devices [*]5V 7.8Wh [*]1560mAh Lithium-Ion Battery Review: I bought mine in a kit from Amazon ($35) but you can also get the stand alone device locally from most Radio Shacks ($40). The Kit comes with the powerport, AC and auto charger, a USB cable and several adapters for different devices including a mini-USB and an ipod/iphone adapter. It's really a simple device. There's a mini-USB port for charging the Powerport (either using a computer or a USB wall transformer), a standard USB port for charging your device (iPhone), and a power switch. It's slightly smaller, thinner, and lighter (2.7 oz vs. 4.8 oz.) than the iPhone itself. My initial charge of the Powerport took about 4 hours. I let my iPhone get down to 20% and then plugged it into the Powerport using the iPhone sync cable. In about 50 minutes my phone was back to 100%. The next time my phone got a 20% warning I repeated the procedure and once again the Powerport was able charge my iPhone back to 100%. I have not tried recharging a third time and probably never will as two full recharges should meet my needs. I also tested the wind-up cable supplied with the device and it appears to work just as well as the stock Apple cable. Both the AC and auto adapter appear to work as direct chargers which is good because my Monster ipod auto charger will not work with the new iPhone 3G. Verdict: I believe that this is a perfect device for my situation. I am confident that I could plug this in during a long flight, watch movies or play some games, and when I arrive at my destination I should have enough battery power to last the rest of the day. It also would have been extremely helpful last week when I went camping!