Is the any way to get a menu when I click on the background in Gnome?

[Chris G]

The subject says it all really.  Is there any way to set up menus
which are activated by clicking on the background in Gnome?  There's on
that pops up by default when you right click on the background but I'd
quite like to have a button 1/left click menu as well.

While I'm about it can I add items to the right click menu?

-- 
Chris Green