I'm sorry, I have changed my mind.
It would take a bit of work, but you might do better to just duplicate the fxtab
In index.php, look for:
<div id="fxTab">
<span class="fxTrigger">Open Control Panel</span>
</div>
Replace it with:
<div class="fxTab">
<span class="fxTrigger"><a href="http://www.yoursecondsite.com>Second Site</a></span>
</div>
<div class="fxTab">
<span class="fxTrigger"><a href="http://www.yourthirdsite.com>Third Site</a></span>
</div>
<div class="fxTab">
<span class="fxTrigger"><a href="http://www.yourfourthsite.com>Fourth Site</a></span>
</div>
Modify the CSS as needed. Note #fxTab and #fxTrigger will need to be changed to .fxTab and .fxTrigger respectively in your css files. Use the 'margin' property to position the tabs. You may need to give each tab div an id in addition to the class(fxTab) to help you exactly place each one.
A bit of work, but doable. Sorry but I can't add more to this... work, and keeping a roof over my family and all that

As always, Firebug is your friend!