Earlier quoted context omitted.
I used to program with a 24" monitor. Then I switched almost exclusively to my 13" Macbook/Pro and haven't looked back. The screen is just the right size to fit two 80x25 text editor windows side-by-side when full-screened. Swiping back and forth with Mission Control is almost as quick as switching your glance from one big monitor to another. Having your "mouse" right below your keyboard makes clicking something only…
Neat bit I picked up on from Mission Control; if you're using the trackpad swipes (vs ctrl-arrow) to switch, if you don't swipe all the way (roughly 1/3 screen), you can "peek" over at the next space w/o switching and spring back when you let go instead of having to swipe back.
Mission Control is pretty fricking awesome.