thought this might be useful to some. http://www.triphp.com/customerror.php you cna created custome error pages rather than the annoying 404 errors.
It's actually pretty useless when you think about it. Especially given that most hosting providers already allow their clients (site owners) to create their own custom 404 files though. Besides, all it does is tells the server where the error page is at. It doesn't actually create one. It is an interesting tool, though.