As a proud owner of an iPhone, it hurts me to say something negative about it, but the battery life is definitely not the best. I was caught out by this little problem recently and I had no way to charge my dying iPhone. I realised that I needed a way of charging my phone throughout the day, but without the hassle of constantly connecting a USB cable.
I looked through all of the iPhone 3GS desk stands available, and the iPhone 3GS / 3G Desktop Dual Charging Dock + Battery Charger caught my attention. Not only is it a standard desktop charger and sync stand, it also includes a portable battery pack that you can use to charge your iPhone when you’re out and about. The Dual Charging Dock has two charging ports so that you can charge both your phone and the battery pack at the same time, and when you leave the house, you simply pop the battery pack into your bag or pocket and off you go.
If and when your iPhone needs a charge, you simple slide your phone into the battery pack and it starts charging immediately.
While I agree that the battery pack is not the smallest, there are other options available like the Mophie Juice Pack. However, the advantage of this one is that you only need to attach it when you need to charge your iPhone, where as the Mophie products double up as a case for your iPhone, which means that it’s attached to your phone permanently and that your iPhone is more bulky. This isn’t really a problem if you want a case for your phone, but I prefer not to use one.