I have used a Dvorak-like keyboard layout since
about 1982. Roughly:
Main differences from Dvorak were to move "a"
from the pinky to the index finger of the left
hand, and to take a few of the less-important
keys and move them back to where QWERTY keyboards
My main reason for using it was that I found it easier
on my wrists than the normal layout, especially when I
was working for Sun, using their awful "Type 5" keyboards.
I have an xmodmap file for X, a Mac OS 9 and
Mac OS X "international-ish" keyboard, and
a hack that works for me on Windows 2000.
Perhaps one of these days, I'll get motivated
and post some of those files.
I have made the occasional USENET posting about my layout ...