My wife Mary was on the hunt for something that would be more petite and not cost a hundred bucks. The iPWR SuperPack is a little square wafer that can be attached to the port at the bottom and iPhone or an iPod touch.
The form factor is the same width and depth as the iPhone and I found it to give the iPhone about twice the battery duration that using the iPhone by itself. Like the Richard Solo 1800 this device makes the iPhone seem too long and a bit awkward, but as an emergency supply of energy for your iPhone it does the job well.
The iPWR uses a standard Mini-USB port that can be found in the majority of handheld devices. This made it very easy to charge on your Macbook or the wall without having to worry that you forgot a special cord. One feature I liked about this unit is that the included USB cable is retractable and therefore always with the device.. The iPRW has the same 1,800mAh type battery that is used on the Richard Solo 1800 and the Mophie Juice Pack
The unit has an on and off switch, which I found useful when I was not using it. the iPRW comes in both a White finish (which I used with my iPhone 3G) and a black finish which Mary has used with both the iPhone first generation and now the iPhone 3GS. Mary actually ended up using both of these units and liked carrying one in her purse and keeps one at work for convenience.
When not attached to an iPhone or an iPod, the iPWR SuperPack has a top lid that covers its connector and USB port. I found this cover easy to lose, but Mary had no problem and she liked having the cap on so that the USB connector would not get caught in items in her purse.
The device has a bright green LED that turns off when the pack is dead, and turns red after a full charge had been completed. This was a convenient way of keeping track of the status of the battery pack at all times. The iPWR is compact, easy to carry, and affordable. Mary uses one of these today as her primary insurance against the Iphone "dead battery syndrome."
I think for the price this little plastic wafer is hard to beat for a quick and easy way to make sure your iPhone or other "iPod" type device has power when you most need it.
Product: iPwr Super Pack