It's been long overdue since I actually wrote this a ways back. I don't know if anybody would find this useful, but I created a pretty simple script written in Perl that will get the latest videos from any of the feeds for any quality type. I've posted it up at http://www.imadethatcow.com/Development/gb_downloader.tar.gz
This is a handy script that can be used in a cron job for grabbing the latest videos on a regular basis. It will not re-download anything you've already downloaded (provided you do not move the video from it's original location). Use --help to find out all the options for running it.
Send me a PM or reply to this topic if you have any questions!