LayoutHTTPHeader allows you to specify a URI that can be used to display headers that will be used across all content. Keep in mind that URI's, while being being regular content are not documents that are meant to be displayed on the web.
A simple perl script example:
Known ProblemsBy overriding Apache's headers you do risk the chance that if Apache had something important to say you are going to miss it. Also, dinking up the HTTP headers can leave you with pages that do not display.