I always write from the desktop. It is born from practice and tradition, but also because it is more functional for me.
Despite being a two digit typist (with killer speed for that set up) I can type without needing to look down. I don’t have very large hands, but the condensed keyboard of my wife’s netbook slows me down more than a few beers would.
I don’t mind this mini qwerty set up on the iPhone, but it is also a loss in speed. Couple that with the fact I have to do a lot of correcting (a good third of my strokes on a regular sized keyboard are backwards strokes) using an unfamiliar system it doesn’t feel like a good match… But it is one that allows me to sit on my back porch after the rain to catch some of the calm after the storm, you know, before the moisture gets sucked back up like a kid trying to get every last drop of Chocolate Quick with a straw.
This format also seems to encourage bloated paragraphs…or maybe that moisture found a place to roost.