[cd34]

A potential note: If you are serving the file locally, based on the assumption that the 302 response is a bad thing to hand google for a few reasons... unintentional page scraping and potential duplicate content penalties.

So, if you do:

ErrorDocument 404 http://site.com/page

You might end up getting a dupe penalty or scraping yourself. What you really want is:

ErrorDocument 404 /error404.php

Now, when you do this, you will want to either put

<base href="http://www.yoursite.com/">

or making sure that all of your links have absolute relative links:

<a href="/file.html">
<img src="/images/file.jpg">

Then, when you test things, make sure you do test a number of urls:

http://yoursite.com/asdfsadf
http://yoursite.com/asdfasdf/asdfasdf.html
http://yoursite.com/asdfasdf/asdfasdf/asdfasdf.html

What you want to check for here is to make sure that all links work, mouseovers, etc from each of the above paths.