screen -x
I have an confession: I don't really like screen. I never have; it's
always struck me as an poor substitute for a real windowing system,
something you only resort to when you can't get the real thing for one
reason or another.
(What really boggles me is the people who aggressively use screen
inside X, winding up with one terminal window with everything inside
a screen session.)
One of the most painful limitations of screen for me has been that you
can't see two screen-bits side by side; you have to keep flipping back
and forth. (Naturally, side by side windows are one of the big things I
use real windows for.)
Then someone I know happened to mention
screen's -x option. To quote the manpage:
-x: Attach to a not detached screen session. (Multi display mode).
Translated into ordinary language, this lets you have multiple windows
connected to the same screen session, where they can then view different
screen-bits. Or simpler: side-by-side viewing of two different
screen-bits; I can get the benefit of windows and screen at once,
if I want to.
The one limitation is that every window really needs to be the same
size, or rather peculiar things start happening. (I like both very
large windows and standard 80x24 windows, so this actually matters
to me.)