This script is residing in /home/metamon/public_html/manifestdensity/2007/01/29/
However, it appears that this isn't the directory where Movable Type is installed — this script couldn't detect the presence of mt-config.cgi.
You may have a very good reason for not putting this PHP file in your MT directory. If that's the case, please use the working directory shown above to figure out the full path of the directory where MT is installed. Here's the code that you'll want to use once you do:
<?php require('/full/path/to/mt/mt-comments-location.php'); ?> <form method="post" action="<?php print $PATH_TO_MT_COMMENTS;?>" name="comments_form"> Rest of the comments form </form>