If external display is connected {"Lid is closed : Do nothing" } else{ "Lid is closed: Suspend" }?

My laptop suspends when I close the lid, as I want it to.

However, when I connect an external display (HDMI) and keyboard (USB), I like to be able to close the lid of the laptop, without suspending the whole system.

Is there a setting or script to get this behavior?

whatever happened since this post first appeared and after making the obvious changes in settings, it now looks as if plugging a mouse and keyboard in is enough to wake the external monitor up whilst keeping the laptop lid closed and its screen off.

This used to be the default behaviour, that regardless of the gnome-power settings the laptop would not suspend upon lid-close with an external monitor present.

The fact that this is no longer the case appears to be a bug. I can't find an existing bug report for it, so I suggest you report a bug on launchpoad.

The only workaround for the moment appears to be to change the gnome-power settings to "do nothing" upon lid close, and use the menus to suspend when you actually want to suspend.