title: how to detect a user has come from a smartphone
body: <p>How can I know if a user has come to my website from a Smart-Phone (especially iPhone and Android)?</p>
  
  <p>I want to redirect the user to a specialized website, so both <strong>PHP</strong> detection and <strong>htaccess</strong> detection are good.</p>
  
  <p>More specifically, the user will come from an <strong>AdWords</strong> campaign. Do AdWords add somwthing to the url concerning that can help?</p>