By now, there are many reviews of the iPhone 3G. They evaluate hardware specs and software features, make speed and pricing comparisons, and foment rumors about future changes. But when it comes to the way technology changes my life, all this information is irrelevant. What’s relevant is the impact of this device, as a whole, on my behavior. Does it improve the quality of my life? Kill bad habits? Save time? Does it encourage responsibility or better organization?

To find out, I had to go buy the phone and start using it. I have had the iPhone 3G for two weeks now, and during this time I’ve paid particular attention its impact on my everyday behavior. So I thought I’d summarize what I’ve found so far.

For me, the iPhone’s unwieldy keyboard and tiny screen provide its greatest behavioral benefits. Its embodied interface inertia has weened me from unhealthy technology habits and has improved my communication. With the iPhone, I write fewer and shorter e-mails, I call people more often, and I don’t browse the web as much.

Here’s what happens in practice. Walking around the city during the day, I’ve found only one way to hold the phone and type on it with more than one finger: cradle it in both hands and use your thumbs to type as you narrowly avoid walking into fire hydrants or other iPhone users. For me, this typing position starts hurting pretty quickly. My thumbs tighten up and get sore from all the flexing, and my wrists start to hurt. It’s true that the iPhone keyboard software is very polished, but compared to a desktop it is almost entirely unusable, even without the wrist problems. I can eek out short e-mails or enter calendar events, but for any serious writing I need a real computer.

So the iPhone is a huge time saver because it’s so painful to use. On a typical pre-iPhone morning, I would wake up and rush to the computer—before doing anything else—to check my e-mail. It’s a terrible habit, and I think it’s pervasive among the folks I hang out with. But the morning after I bought the iPhone, I woke up and checked my e-mail before even getting out of bed, and when I was finished I didn’t feel compelled to approach my real computer before breakfast. This morning, for example, I actually read a book! I spent an hour reading before even going near my desk. This habit has stuck since day one, and I’m loving it.

The iPhone has also encouraged me to find new ways to communicate. Let’s say I get an inspiring e-mail from someone that generates lots of ideas. On the computer, I would reply with a brain dump, maybe spending an hour crafting a message. But with the iPhone, I’m reluctant to type more than a sentence. Maybe I call the person instead. Voice conversations are so much more efficient and intimate than e-mail. And yes, sometimes a long e-mail is warranted, in which case I can sit down at the computer and really focus on it.

My web browsing habits have changed, as well. I’ve spent way too many days of my life staring blankly at random web sites. But Mobile Safari requires so much patience and determination that I don’t use it unless I really, truly need it. This is the feature I’ve always wanted in a web browser, and the iPhone delivers!

A side effect of these changing habits is that my computer is now reinvented as the place where only real work gets done. If I sit down at the computer, it is because I have a task in mind. As long as I can pull myself away when that task is done, I’ll be much more efficient with it. And it’s easier to pull myself away if the computer isn’t so overloaded with different functions in my life.

Google Maps invoke the other big behavior change. I needed to find a good cafe the other day, in an unfamiliar neighborhood. Normally this would entail 20 minutes of wandering around. But I quickly found something within one block. I’m always in the position to suggest something nearby, or to look something up, and I’m really happy about that.

Beyond that, there isn’t much. What about the amazing touch interface? The WiFi? The App Store? The iPod features? I suppose I can cite Terry Gross more often now, but in general these features haven’t had a big impact on my behavior, they’re just nice to have. Also, there are lots of iPhone games and other applications that I haven’t delved into yet, so I’m excited about opening up more good-behavior potential from this device. I’ll let you know what arises…