Yeah, I have seen some kool 404 error pages in my days! If you should check out quantumcloud.com has a kool 404 page too. Just type in any wrong url like
www.quantumcloud.com/givemetheerrorpage.htm and you will see it. Again to do it you will need apache with .htaccess enabled. If you have that then it's just a snap. You will need to write something like this in a textpad:
ErrorDocument 401 /forbidden.htm
ErrorDocument 403 /forbidden.htm
ErrorDocument 404 /nofile.htm
Then save it as .htaccess in the root folder of the website. The code above not only works for page not found 404 error but also for 401/403, forbidden page error. You may also want to consult your web host to find out the exact method of doing it.
[http://www.plinko.net/404/area404.asp]
Has many links to some stunning error pages on the web.

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