I haven't gotten around to getting a Treo or BlackBerry yet, but I still text with the greatest of ease thanks to the T9 text input system on my Sony Ericsson phone. (In a nutshell, I use the number pad to type out each word, and the input system figures out which word I most likely meant. It's remarkably accurate, and remarkably quick.) But according to an Associated Press article appearing in Technology Review, I may actually be experiencing only the second or third greatest of ease.
In 2004 a company called Digit Wireless introduced a new system called Fastap, which adds 26 tiny buttons -- one for each letter -- to your phone, most of them in the corners between each number. I'd have thought that this would be more annoying, but it turns out that Digit Wireless's experience says otherwise. Phones with Fastap keyboards have only been sold through two providers: Alltel in Arkansas and Telus in Canada. People have taken such a liking to the system that on average, Fastap users send more than twice as many text messages as not-Fastap users. (Of course, someone who isn't interested in texting wouldn't bother to look at a phone with Fastap, but still.)
If the Fastap system catches on, then heavy texters might just have an easier time of it in the near future. Phsyiotherapists, you might want to start your thumb-specialization studies now.