[Kane@airrifle]

Another more inelegant way would be to edit the memberaction_dropdown template

Replace default code with.

<div class="popupmenu memberaction<vb:if condition="$page_class"> {vb:raw page_class}</vb:if>">
        <a class="username {vb:raw memberinfo.online} popupctrl" href="{vb:link member, {vb:raw memberinfo}}" title="{vb:rawphrase {vb:raw memberinfo['onlinestatusphrase']}, {vb:raw memberinfo.username}}"><strong><vb:if condition="$memberinfo['musername']">{vb:raw memberinfo.musername}<vb:else />{vb:raw memberinfo.username}</vb:if></strong></a>
	<ul class="popupbody popuphover memberaction_body">
                <vb:if condition="$show['member']">
		<li class="left">
			<a href="{vb:link member, {vb:raw memberinfo}}" class="siteicon_profile">
				{vb:rawphrase view_profile}
			</a>
		</li>
		
		<li class="right">
			<a href="search.php?{vb:raw session.sessionurl}do=finduser&amp;userid={vb:raw memberinfo.userid}&amp;contenttype=vBForum_Post&amp;showposts=1" class="siteicon_forum" rel="nofollow">
				{vb:rawphrase view_forum_posts}
			</a>
		</li>
		
		<vb:if condition="$show['pmlink']">
		<li class="left">
			<a href="private.php?{vb:raw session.sessionurl}do=newpm&amp;u={vb:raw memberinfo.userid}" class="siteicon_message" rel="nofollow">
				{vb:rawphrase private_message}
			</a>
		</li>
		</vb:if>
		
		<vb:if condition="$show['viewblog']">
		<li class="right">
			<a href="{vb:raw $vboptions.vbblog_url}{vb:if "$vboptions['vbblog_url']", '/', ''}blog.php?{vb:raw session.sessionurl}u={vb:raw memberinfo.userid}" class="siteicon_blog" rel="nofollow">
				{vb:rawphrase view_blog_entries}
			</a>
		</li>
		</vb:if>
		
		<vb:if condition="$show['homepage']">
		<li class="left">
			<a href="{vb:raw memberinfo.homepage}" class="siteicon_homepage">
				{vb:rawphrase visit_homepage}
			</a>
		</li>
		</vb:if>
		
		<vb:if condition="$show['viewarticles']">
		<li class="right">
			<a href="{vb:raw memberinfo.author_list_url}" class="siteicon_article" rel="nofollow">
				{vb:rawphrase view_articles}
			</a>
		</li>
		</vb:if>

		<vb:if condition="$show['addfriend']">
		<li class="left">
			<a href="profile.php?{vb:raw session.sessionurl}do=addlist&amp;userlist=buddy&amp;u={vb:raw memberinfo.userid}" class="siteicon_add">
				{vb:rawphrase add_as_contact}
			</a>
		</li>
		</vb:if>

		<vb:if condition="$show['emaillink']">
		<li class="right">
			<a href="sendmessage.php?{vb:raw session.sessionurl}do=mailmember&amp;u={vb:raw memberinfo.userid}" class="siteicon_email">
				{vb:rawphrase send_email}
			</a>
		</li>
		</vb:if>
		{vb:raw template_hook.memberaction_dropdown_items}
	</ul></vb:if>
</div>

This will have the effect of blocking the whole UL to guests, everywhere.