The reason is simple, and unfortunately, has nothing to do with magic.
A good friend of mine has recently been raving about the Mophie Juice Pack, which claims to double the battery life of the iPhone 3G, adding an extended 6 hours of talk time, but more importantly, letting you watch back to back movies on a coast to coast plane ride without any noticeable impact.
As a hardcore iPhone user, this sounded like a must-have. Even despite the fact I've never gotten a backup battery for my laptop, a powered off battery for the iPhone is something I've seen all too often.
So I went to the Mophie Web site, searched for where they were sold, and found I could be served at the Valley Fair Apple Store in San Jose. So off we went! But when I arrived at the Apple Store, I could not find any Mophie, and no sales rep I talked to knew where they were.
The InCase Power Slider acts as a case, and a Power Extender
But I was not out of luck, as I spotted the Incase Power Slider, which not only also doubled the iPhone's battery life, but doubles as a comfortable, if not too bulky, case. After I got home, I powered up the case, powered up the iPhone, connected the two, and ever since, I've been practically worry-free when it came to power.
Instead of hooking up my iPhone to power every day (if not multiple times a day), I charge both devices every few days, and I haven't run out of power a single time.
Some of the reviews on Amazon say the case reduced their cell phone reception, but I haven't seen that at all. The only complaint I would even think to raise is that the added bulk to the iPhone means I can't put it in my beltclip, therefore, not having a case within a case. But if you're a power user of the iPhone, and you've learned to juggle your 3G access just to keep the device on, I would absolutely recommend looking into either the InCase product or that of Mophie. Doubling your power is a great thing.
Of course, this would all be moot if we just could get wireless power adapters... like I've been talking about for a long time.