Obstacle to the iPhone's Success: Can You Use It With One Hand?

Many people have criticized the iPhone without ever touching one. It's funny to note that most of the criticism focuses on things like the price of the phone (Steve Ballmer), or John C. Dvorak saying Apple can't survive the thin margins of the cell phone business. But what about the phone? Dvorak and Ballmer make no prediction whether people will like using the phone.

Let's focus on the functionality of the iPhone, because ultimately, that's where the battle will be waged. Apple can turn a profit on the device as long as it can sell a product that is better than any other of its kind. If they do that, they can follow luxury car companies and sell in smaller quantities for a lot more money.

Keeping Your Eyes on the Road

My first question for the iPhone is, can you use it with only one hand?

Picture yourself driving with your cell phone in your pocket. It rings. You know it's dangerous to talk on your phone while driving, buy you decide to answer anyway. Keeping one hand on the wheel, you reach your hand into your pocket, take out the phone, and with your thumb, you answer, either by flipping open the phone or by hitting the talk button. You do it without taking your eyes of the road. Will you be able to do all of this with the iPhone?

At 2007 MacWorld, Steve Jobs said making calls is the iPhone's killer app. That's making calls, not receiving. He never demoed receiving a call while the iPhone was not already in use. For the sake of discussion, let's call answering the iPhone from locked mode a cold call. The only reference to a cold call at 2007 MacWorld was when Jobs showed a slide of the iPhone as it presumably received a cold call. The slide showed two buttons on the iPhone, one to answer the call, one to ignore it. Would it be possible to hit those buttons with your thumb? Will the promixity sensor allow the button to be pushed if it detects your palm reaching across the phone?

Now, let's take a step back to my scenario of answering the phone while you're driving. The iPhone is in your pocket and it starts ringing. Without taking your eyes off the road, you take it out of the pocket and attempt to answer the call.

Can you tell which part of the phone is the top, and which is the bottom?

Assuming you know which way is up, how do you know--eyes on the road now-- you are hitting the correct button? The screen is smooth--there is no tactile feedback or any other distinguishing feature. Will our motor memories be enough to know which section of the screen to push?