I have seen code similar to this, however it does not do everything I needed.

I am using imagemagick to perform the screen grab. It has features for grabbing the window under the cursor and rubber-banding regions with the mouse. I particularly like the -frame option that allows the image to capture the window manager frame. Being a separate application, it must be installed on the linux platform for it to work. It can be downloaded from:

http://www.imagemagick.org/script/index.php

PS. The command line invocation for imagemagick is a bit misleading. The command to make a screen grab is

import -frame some_pic_name.jpg
[download]

Cheers, Tim