Here is a 3-in-1 external battery pack that adds DUAL SIM function to the iPhone 3G/3GS. The battery pack includes the Q-Dual Dual SIM card adapter that allows your iPhone 3G/3GS to use two SIMs. Users can easily switch between the two SIMs on the iPhone.

iPWR introduces the SuperPack external battery for iPhone 3G mobile phone. This compact SuperPack has a 1800mAh Lithium-Polymer battery inside that can double the operation time of your iPhone 3G. It can change the iPhone from 0% to 100% in under 2.5 hours.

mophie has previously introduced the Juice Pack external battery, the company now offers the ultra slim Juice Pack air rechargeable external battery for iPhone 3G. Based on a rechargeable 1200 mAH lithium polymer battery, Juice Pack air has an ultra-thin, light-weight, low-profile design and is the thinnest Apple certified “Works With iPhone” external battery in the world.

SolLight offers the SOLiCharger, a soloar-powered rechargeable backup battery for iPhone and iPod touch. The SOLiCharger is a small lightweight Lithium-ion battery pack that can be charged from solar power. It offer iPhone or iPod touch up to …

PhoneSuit introduces the MiLi, another power pack for iPhone. The MiLi works with both iPhone 2G and iPhone 3G. It has a 1800 mAh battery offering:

Standby time = 350 Hours
Talk time …

Incase offers this Power Slider battery case for the iPhone 3G. Like Mophie’s Juice Pack, the Power Slider offers expanded battery life for your iPhone, but this Slider delivers more by …

FastMac releases the iV extended battery and portable charger for iPhone, both 2G and 3G. FastMac iV offers up to 24 hours of talk time, 750 hours of standby time and up to 21 Hours …

The battery life of the iPhone 3G is not enough for you? Consider Mophie Juice Pack for iPhone 3G, a external battery pack. The Juice Pack 3G is a rechargeable lithium polymer battery in the form of a non-slip, soft grip case.

The Juice Pack offers up to 350 hours of standby time, up to 6 hours of of talk time and internet use for iPhone 3G, up to 28 hours of audio playback and 8 hours of video playback time.

Here is an interesting case for your iPhone, Solar charging case. Not only does the case protect your iPhone from damage, it can also charge your iPhone 3G on the move using solar energy.

The case comes with a 1,500mAh battery pack for storing …

As we all know, we are not able to change the battery of our iPhone or iPod, and thus Kensington’s new offering may be what we need. Kensington’s new Battery Pack and Charger for iPhone and iPod are rechargeable …