My current programming project is proceeding rather slowly, due to lack
of time. Most days, I get literally a few minutes in a coffee break
actually at a terminal. But there's always plenty of thinking time--on
the walk to work, in the shower, or while washing up. Rarely with pen &
paper to hand, unfortunately. I can't say that this is my favourite way
to program, but it does help correct my tendency to spend too long
tapping the keyboard, with insufficient cogitation.