How can I lock down my entire site?

[eluser]Aquillyne[/eluser]
This works:

post-controller-constructor

Code:

class Lock
{
    
    var $locked = TRUE;
    var $CI;
    
    function check()
    {
        $this->CI =& get_instance();
        
        if ($this->locked)
        {
            $data["PageTitle"] = "LOCKED!!";
            $data["Content"] = "LOCKED!!";

            $this->CI->load->view("locked", $data);
            $this->CI->output->_display();
            die();
        }
    }
    
}

Can anyone say if I'm doing anything a little clumsily here? Or is this fine?

The problem remains: how to alter whether the site is locked via the button in the admin area...