Here is a simple solution for this:
Find in header template:
Code:
<li><a href="{vb:link member, {vb:raw bbuserinfo}}">{vb:rawphrase your_profile}</a></li>
Under that paste in:
Code:
<li class="popupmenu nonotifications" id="Site_Switcher">
<a class="popupctrl" href="usercp.php">Switch Site</a>
<div class="popupbody popuphover" style="margin-left:100px;">
<p><a href="http://nyspeed.sagemind.net">NYSpeed.com</a></p>
<p><a href="http://son240.sagemind.net">SON240sx.org</a></p>
</div>
</li>
Adjust the "margin-left" value to get your drop down aligned properly, and change the id to whatever you want it to be.
Here is what this produces: