I am loving this spectacular multi-level folder/file structure layout by Louis Coyle. It has a nice grid layout with a list of folder and files and on clicking the folder it drills down into that folder and shows the user the contents of that folder. This will work well on sites where you want to have a directory structure and allow users to jump in and out o the various directors in there.
Multi-Level Folder Structure with Click to Drill Down Layout
Multi-Level Folder Structure with Click to Drill Down Layout GIFImage: