Redirect mobile visitors from drupal site to mobile site on other domain.

 Your best way would be to write a small module and implement hook_init()

  function MYMODULE_init() {
    include(“PATH/TO/Mobile_Detect.php”);

    $detect = new Mobile_Detect();
    if ($detect->isMobile()) {
    header(‘Location: http://thirstysix.com;);
    drupal_exit();
    }
  }