I was just noticinng the dull, usual "Not Found" page, and I was thinking it might be a good idea to make a customized error page that goes with Chickscope's template. I'm not sure what server this is, but if its apache or ncsa HTTPd you can just put a error document directive into the server to tell it to execute a CGI script or go to a page. I set one up at my school's site here:
http://www.uni.uiuc.edu/bad_link
Also, since it's a CGI script you can make it write to a log or e-mail someone.