how to focus on desktop automatically if no windows open?

[Brandon Kuczenski <brandon 301south net>]

I'm using Gnome 2.10.2 on Debian.  Sometimes I like to use the keyboard 
instead of the mouse to navigate the desktop.  However, if I close a 
window (using, e.g., M-F4) I go into what appears to be a 'no-focus' 
state: pressing the arrow keys, tab key, enter, etc.. doesn't do anything.

I know I can bind a key to "Hide all windows and focus the desktop" in the 
Keyboard Shortcuts dialog; is there any way to focus the desktop by 
default if no windows are open?

-Brandon