I, personally, like the 404 pages with missing kids on it. The only real purpose of the 404 page is to tell the user he messed up somehow; you might as well do some good with it.
Telling the user that "he/she" messed up is the best way to get them to abandon your website.
Clearly explaining that there was a problem, the problem has been sent to the appropriate individual, and guiding them to potential solutions is a better approach.
Clearly explaining that there was a problem, the problem has been sent to the appropriate individual, and guiding them to potential solutions is a better approach.