It looks like a simple edit of the
navbar template.
Open your navbar template
Find the code:
Code:
{vb:raw template_hook.navtab_end}
Directly above it add your custom HTML, make sure it is inside <li> </li> tags...
Something like:
Code:
<li><a href="http://www.twitter.com"><img src="images/twitter_icon.png" border="0" title="Visit Twitter" alt="Twitter"></a></li>
Repeat that for each icon/image you want, customizing the URL and images obviously for your needs.