I suppose you could use EZ-Pages for navigation. It depends on what you want to link to.
Take a look in includes/templates/YOUR_TEMPLATE/common/tpl_header.php
Code:
<div id="headerWrapper">
<!--bof-navigation display-->
<div id="navMainWrapper">
<div id="navMain">
<ul class="back">
<li><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">'; ?><?php echo HEADER_TITLE_CATALOG; ?></a></li>
<li><a href="http://somesite.com">your link here</a></li>
<li><a href="http://anothersite.com">another link here</a></li>
I used to have something like this on one of my sites, but I removed it recently since I moved the Zen Cart to the root.