remove the three link from ul and put the below code after the '</ul>'
tag
<div style="float:right">
<ul id="dropmenu">
<li><a linkindex="84" href="http://www.youtube.com/mradamduckworth">YouTube</a></li>
<li><a linkindex="83" href="http://www.facebook.com/aduckworth2">Facebook</a></li>
<li style="margin-right:35px"><a linkindex="82" href="http://twitter.com/#!/mradamduckworth">Twitter</a></li>
</ul>
</div>
whole code will be like this
<div id="nav">
<ul id="dropmenu">
<li ><a rel="bookmark" title="Home" href="http://mradamduckworth.com">Home</a></li>
<li class="page_item page-item-2"><a href="http://mradamduckworth.com/?page_id=2" title="About">About</a></li>
<li class="page_item page-item-5"><a href="http://mradamduckworth.com/?page_id=5" title="Directing">Directing</a></li>
<li class="page_item page-item-31"><a href="http://mradamduckworth.com/?page_id=31" title="Acting">Acting</a></li>
<li class="page_item page-item-33"><a href="http://mradamduckworth.com/?page_id=33" title="Other Projects">Other Projects</a></li>
</ul>
<div style="float:right">
<ul id="dropmenu">
<li><a linkindex="84" href="http://www.youtube.com/mradamduckworth">YouTube</a></li>
<li><a linkindex="83" href="http://www.facebook.com/aduckworth2">Facebook</a></li>
<li style="margin-right:35px"><a linkindex="82" href="http://twitter.com/#!/mradamduckworth">Twitter</a></li>
</ul>
</div>
</div>
but this following html code will be replace with WP menu function
<li ><a rel="bookmark" title="Home" href="http://mradamduckworth.com">Home</a></li>
<li class="page_item page-item-2"><a href="http://mradamduckworth.com/?page_id=2" title="About">About</a></li>
<li class="page_item page-item-5"><a href="http://mradamduckworth.com/?page_id=5" title="Directing">Directing</a></li>
<li class="page_item page-item-31"><a href="http://mradamduckworth.com/?page_id=31" title="Acting">Acting</a></li>
<li class="page_item page-item-33"><a href="http://mradamduckworth.com/?page_id=33" title="Other Projects">Other Projects</a></li>