Auto-Resolution-Detection of External Monitor?

[Andreas Schildbach]

Hello everyone,

I've configured X 6.8.2 on my Notebook in a Dualhead/Xinerama configuration.

I have several places where I use the notebook, one with an external 
1920 x 1200 display, one with a 1280 x 1024 display and one place is "on 
  the road" with no external display at all.

Currently, I have to switch resolutions by hand. Is there any way to 
configure X so it automatically switches to the resolution of the 
monitor that is connected? And would perhaps shut down the secondary 
head if there is no monitor connected at all?

Detection at boot-up time would be sufficient.

Detection at video cable connect time (while the notebook is running) 
would be perfect.

Regards,

Andreas