Ize on forums.xbox-scene.com released a tool that will allow you to easily reduce the size of your Xbox360 games (for homebrew Xbox360s):
[QUOTE]
I've thrown something together that at least batch removes systemupdates and replaces moviefiles with placeholders, it can also delete alot more based on simple config files.
I assume that you are saving your games in xexloader / xexmenu compatible path like: USB://Games/Game
You just select the folder usb://games and the program will scan for systemupdates, movies and if available for smart cleaner files (who isn't really that smart ;p) compatible games