How I've tackled this problem in the past: 1. Create a 404.php (or whatever your preferred back-end is) 2. mod_rewrite real 404s to serve that script. 3.

How I've tackled this problem in the past: 1. Create a 404.php (or whatever your preferred back-end is) 2. mod_rewrite real 404s to serve that script. 3. In that script have a lookup table/db/file that lists all the redirects you need. 4. Extract the requested URL from the server variables. 5. Use the lookup table to find the correct URL, and issue a 302 for it to the users browser. It's kinda seamless, and I've been doing it for years.