Really simple: Add a header and footer on every page
//controller
$this->load->helper('url');
include('header.inc');
$this->load->view('content');
include('footer.inc');
//header.inc //top menu
<div>
<a href="<?php base_url() ?>;" title="Home Page">Home</a>
<a href="/forum/" title="Drop us a note.">Forum</a>
<a href="/about/" title="Learn about us">About</a>
</div>
//footer.inc
<div><span>Copyright Me 2009 -</span><span>Page rendered in {elapsed_time} seconds</span></div>