Crave UK's Rory Reid did a great experiment: Test the typing accuracy of the iPhone vs an Asus Netbook in a rally car racing at full speed. The video and the results will surprise you.
Jump to minute 2:00 to get into the test itself:
Yes, the iPhone wins. Even with its software keyboard, it proves more accurate than the netbook's tiny keys. I think I see him doing some finger sliding with the iPhone at one point—which is a good way to get accurate typing under stress conditions—but my guess is that the iPhone word prediction and correction did the rest of the trick.
Some will argue that this test is too extreme and it will not happen in real life. Obviously, those people have never ridden the New York City subway, which sometimes gets pretty close to this experience. Specially in some of the express lines, which feel like a amusement park crazy ride rather than a train. Sure, maybe the subway turns don't generate three times the force of gravity, but to me it feels close enough. [Crave UK]