Ok, I have two monitors connected to the Linux box. I am running Linux at 1920x1200 on the 24" screen. I want to also output the same desktop to the 20" monitor at 1680 res. So if both monitors are on I will see the same desktop on both, but at each monitors native res.
However I wouldn't actually use both monitors for Linux at the same time. I would only use the 20" monitor if the 24" is not available as I'm using windows on it.
After further reading I don't think it's possible to clone the linux desktop at different resolutions. But perhaps I can create some kind of shortcut to easily change the resolution?
Edit
OK, I found out about krandrtray which does what I need. Appears I have to change from the system tray though and can't setup a keyboard shortcut