Is it possible to get the contents of a remote directory using HTTP? I know programs like Go!Zilla have options to leech from websites, where you can see all of the files present at the site and whatnot...I''m just wondering how they do this.

On a properly configured server, all you can do is examining links that don''t leave the domain, combine that with some more common files (like robots.txt) and see what structure you end up with. If the server it configured to allow directory indexes and you GET an URL that (1) only describes a directory, like http://www.example.org/somedir/ and (2) for which the server does not have a default index file like index.html, you will get the server''s favoured form of directory listing. It is pretty easy to parse this listing based on knowledge of the server software.