It's not good news for iPhone users as a recent study shows that typing on the device is slower than many other mobile devices.
("Research firm User Centric has released a study that tries to gauge how effective the iPhone's unusual on-screen keyboard is. The goal is certainly a noble one, but I can't say that the survey's approach results in data that makes much sense. User Centric brought in twenty owners of other phones--half who had ones with QWERTY keyboards, and half who had ordinary numeric phone keypads. None were familiar with the iPhone. The research involved having the test subjects enter six sample text messages with the phones they already had, and six with an iPhone.
Logical end result: These iPhone newbies took twice as long to enter text with an iPhone as they did with their own phones, and made lots more typos. But given that they were being confronted with an iPhone for the first time, I'm actually startled that they fared as well as they did. And just about any text-entry system is confounding at first, including other phone-based options like T9, Graffiti, and even the relatively straightforward physical keyboards on a BlackBerry or Treo. (Even a full-sized, typewriter-style PC keyboard is a major challenge to learn--it's just that most of us did so long enough ago that we've forgotten the angst.)")