Yeah, I'll put it in the thread, because it doesn't look like it's out there yet:
if you put an html document in the root folder, you can navigate to it at
file:///mnt/us/index.html.
If you put a link to the system root in that document, you can get there, and it will list the directories.
Code:
<a href="/">FS Root</a>
If you click that link, the title bar of the browser changes to "OMG!", and you can follow the directory path, without errors.
Not all folders are available though, for example "/usr/bin" is not available, but "/usr/java/lib/fonts" is, which isn't too useful.
I have not yet tried putting in an href to one of the folders that doesn't shop up on the list, if anyone wants to try.
one problem, is that you cannot use the back button, because that correctly triggers the protections, same as if you had tried to put /etc into the address bar manually.
I wonder if Javascript and a frame could be used to take care of that issue.