VNC extra monitors
A couple of times in the past I've thought about using other computers/tablets as additional displays for my main computer.
This time I actually found a way to do it.
xrandr can be used to create a new monitor without the need for an actual monitor, I used the
VIRTUAL1 output and was pleased to see a
VIRTUAL2 pop into existence when I did. Then
x11vnc with an appropriate
-clip can make a VNC server for that bit of the virtual desktop.
I tried both a spare laptop and my tablet as extra displays and it seems to work well with either.
The tablet as extra screen will be quite nice when I'm travelling.