Hi,

Do any of the mainstream control panel programs offer the feature of turning on a custom 404 page server wide?

I am looking into getting a dedicated server to host nearly fifty sites I have and would like to have a central error page for all of my sites.

No, but you could just hand edit the httpd.conf and set Errordoc 404 http://www.blah.com/404.html
Globally..

If you will be using CPanel you could put all error documents and other standard pages in the skeleton directory which is copied to each domain you create an account for ~ Gem