Specifications
The GoMobile Charger can charge four AA or AAA batteries at a time and my test unit came loaded with two AA and two AAA batteries. The device includes an AC adapter and a DC car adapter for charging on the road. The Instant USB charger is a much smaller device with an internal battery that is designed to power any USB device. The battery pack is 5V 1150mAh unit promising 180 more minutes of talk on the iPhone 3G.

In Use
Duracell doesn’t quote run times for the iPhone 3GS, which would likely be close to the same as the iPhone 3G. In use, the Instant USB Charger was able to juice my iPhone about half way full before running out of power itself. The gadget has a micro USB port on one side for charging it from your computer USB port and the other has a full size female USB port for connecting your gadgets.

The form factor of the instant USB Charger is great. The thing is very small and is about twice the width of your typical flash drive. You can slip the battery into a pocket and carry with you easily or keep it packed in your car for emergency use.

The larger GoMobile Charger is the perfect answer for how to keep those AA or AAA battery using gadgets powered on long car trips. The thing can charge wither four AA or four AAA batteries at the same time and it ships with a DC adapter for your car and an AC adapter for your home

The charger does exactly what you expect it to do, namely charge the batteries. It takes one hour to recharge the batteries fully so with two sets of AAA you can have virtually endless power for your gadgets since most will run longer than an hour.

The charger is average size for an AA charger, which is to say it is a bit large. You may have a hard time fitting the thing into your backpack or brief case, but it's not really meant to be used outside the car or home anyhow.

The only downside to the GoMobile charger would have to be its size put the thing on the AC outlet and you lose the other plug on the outlet. The downside to the Instant USB Charger is that you need to take your own charge cable with you on the go. It would be nice to see tips allowing the thing to charge devices without needing your charge cable.