Fantasy author Peter Brett tapped out a 100,000 word novel on one of those industrial-grade HP iPAQs -- bigger than a standard smartphone, but a thumb-board all the same!
In late 2005, HP came out with the iPAQ smartphone 6515 with Windows Mobile which did the same thing as the Palm Pilot, but had a full keyboard so you didn't have to write with the stylus--you could just type. I thought it was the greatest thing ever and bought it right away. As I got faster and faster typing with my thumbs, I wound up just writing prose on it. After doing that for a while, and realizing I could do it from anywhere, I made a commitment to myself to write on the train everyday.
He would walk through busy streets, cranking out prose. Eventually, his text files got too long for the old HP to cope with, and he upgraded to the iPaq 900.
"One of the main reasons I never bought the iPhone," he told Laptop Mag, "was that I tried writing with virtual buttons, and it just couldn't keep up with me."