Screen for collaberation
GNU Screen is often used for keeping programs running while their user is logged out, but it is also very useful for collaboration when more than one user connects to a session. To do this, "multiuser on" must be set in the session, either in the screenrc file or with ctrl-a :multiuser on in the session. Then the user who didn't start screen must connect to it with screen -r and the username of the owner of the session and the name of the session like "screen -r nick/31346.pts-15.lion".
The name of the session can be found by the owner doing screen -ls or root looking in /var/run/screen/ in the owner's session directory where there is a named pipe with the name of the session. The screen binary must be setuid root with chmod u+s and owner root. The session owner must explicitly allow the other users to connect with "addacl otherusernames" either in the screenrc or in the session. Then when both users are connected they have the privileges of the session owner and can see what each other are doing, allowing demonstration of various system tasks or issues.
Screen for logging serial consoles
so prgmr.com uses screen for logging serial consoles. here is the foo we put in .screenrc:
screen -L -t boar /dev/ttyUSB0 115200,cs8
where boar, of course, is the title of the screen window (Should probably match the host being monitored)