title: PHP login system: Remember Me (persistent cookie)
body: <p>I'd like to add a "remember me" checkbox option before logging in.</p>
  
  <p>What is the best way to securely store a cookie in the user's browser?</p>
  
  <p>For example, Facebook have their "remember me" checkbox so that every time you enter facebook.com you are already logged in.</p>
  
  <p>My current login uses simple sessions.</p>