Steven Levy, another satisfied adopter of Apple's smart phone
Wired Magazine
http://www.wired.com/gadgets/gadgetreviews/magazine/16-10/ts_levy

Steven Levy: Why the iPhone Is Almost Perfect
By Steven Levy   09.22.08

My first full day with the iPhone 3G turned out to be too full. At
least as far as the iPhone was concerned. It was just two in the
afternoon when the screen displayed the most unwelcome dialog box in
mobile computing: LOW BATTERY: 20% OF BATTERY REMAINING. In my
experience, that message's real meaning is make your last call NOW,
because the lights are going out soon. Though it didn't happen
instantly, within a few minutes that gorgeous screen looked like the
closing shot of the The Sopranos finale.

I had been enjoying the iPhone 3G. The out-of-the-box price was right
— as low as $200, with a two-year contract — if you qualify for the
subsidy from AT&T. It was slimmer and sleeker than its predecessor. It
had real GPS. And, addressing my biggest problem with the original
iPhone, data loaded much faster when a 3G network was available. Most
of all, I was itching to try out loads of the intriguing applications
from the iTunes App Store, about a dozen of which I'd already
downloaded. But there's no joy in a juiceless phone.
How bad is the problem? No way around it — 3G cellular chips eat
energy. But Apple's Bob Borchers contends that the iPhone team
succeeded in extending battery life to an acceptable level. There's
evidence to back this up: The iPhone does best its 3G rivals when it
comes to run time.

Nonetheless, battery life is more of a challenge for the iPhone than
for its competitors, because Apple's multitouch darling entices you to
actually do the things that burn through your charge like a Roman
candle. It's so easy to surf the Web, play graphics-intensive games,
and geolocate your buddies that the iPhone is less likely to hang out
in your pocket in standby mode, waiting for a silly phone call.

The Bottom Line? Battery issues hinder an otherwise stellar mobile
computer.
"iPhone apps are a game changer," says Tim Westergren, founder of
Internet radio company Pandora, whose music app — an early favorite of
iPhone downloaders — perfectly illustrates the power problem. When you
listen to audio stored on the iPhone, you can indulge in 24 hours of
tunes without a recharge. But streaming Pandora will run the battery
down in maybe five or six. According to Westergren, Pandora's growth
rate doubled after the launch of the new iPhone — a phenomenon
undoubtedly mirrored on thousands of battery meters.

Part of what's happening is that we have unrealistic expectations from
tech in general. We're so used to technomagic that we routinely expect
some chemist or physicist — or clever geek at Apple — to come up with
solutions to our problems. But while computing power and storage make
advances in logarithmic scale, batteries seem to follow Not Much
More's law. It's a problem for not just phones but everything from
electric cars to hearing aids.
That said, power consumption is not a dealbreaker for the iPhone 3G.
Think of it as a chronic condition that requires monitoring and
treatment. All over the blogosphere you'll find the Apple fanboy
version of Hints From Heloise: iPhone 3G battery-extension tips.
Apple's own Web page on the subject instructs users to dive into the
Settings menu to turn off power-draining features. (The last
suggestion is "Turn off 3G," an odd request for a product whose name
includes "3G.")

But the best advice is to put expectations into perspective. "This is
as much a computer as a phone," says Matt Murphy, who heads Kleiner-
Perkins' iFund, a $100 million initiative that seeds iPhone apps. "You
don't expect a computer to last for 24 hours on one charge."
Since that first meltdown, by taking battery- extending measures like
switching off push mail, data fetch, and sometimes (sniff) 3G, I have
only occasionally had a day where I needed to break out the charger
before bedtime. One day we'll get that quantum leap in battery tech
that will obviate the annoying trade-off between functionality and
juice. Until then, it's so many apps to play with, so little time
between charges.