I've got it solved: I don't move, so I have no need for mobile devices.
This is actually semi-serious. After years of being on the bleeding edge of things - anyone else here have an early Apple Newton? - these days I don't get out much, and when I do, a pen and paper usually suffices. I need quiet and time to concentrate to write, the most that comes at other times are ideas that I might explore when I have the time.
I have a notebook computer for extended periods away, and I'm thinking of updating that to something like an Asus Transformer - whatever I get has to support a proper keyboard, I think through my fingers.