While more flexible, the .htaccess approach is intrinsically riskier than Ovid's, because you must pass a directory or file derived from untainted user data to a system call (ie. opendir, or open). This means you have to carefully consider all classes of valid input versus invalid and potentially dangerous input. From a security perspective, it's preferable to have a simple mapping of user input to prearranged file locations.

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print