The Web Developer Toolbar for Firefox has a great tool called "Display Ruler" - but it is buried in the menu and I'd like to be able to set up a keyboard shortcut for it.

This is not in the Application Menubar, so I can't set it up in System Preferences.
I have the KeyConfig extension for firefox, but I don't see any menu option for this item.

The Web Dev toolbar has a keyboard configuration tab, but it doesn't have an option for the ruler tool:
