I am using Apache's mod_rewrite to redirect mobile users to my mobile site based on their http_user_agent. However not all pages have a mobile equivalent. Also mobile pages end in .html and "full" pages end in .shtml. Here is some pseudo code. Does the user have a certain HTTP_USER_AGENT? Is there a mobile page? If so take them there. If not, no redirection is needed. I want to do this with apache.