[Adrian Schneider]

Here is what I'm using... It's not perfect yet, but it's pretty close.

PHP Code:

function buildForumTree($forumid = -1, $depth = 0, $collapseDepth = 1)
{
    global $vbulletin;
    
    $forumbits = '';
    foreach ($vbulletin->forumcache as $forum)
    {
        $permissions = fetch_permissions($forum['forumid']);
                
        if (
            $forum['depth'] != $depth or
            $forum['parentid'] != $forumid or (
                !($permissions & $vbulletin->bf_ugp_forumpermissions['canviewothers']) and
                !$vbulletin->options['showprivateforums']
            )            
        ) continue; 
                    
        $forum['childArray'] = explode(',', $forum['childlist']);
        $forum['subforums'] = count($forum['childArray']);
        
        $show['collapsesubforums'] = ($depth == $collapseDepth and $forum['subforums'] > 2);
                
        $childForumBits = ($forum['subforums'] > 2 ?  
            buildForumTree($forum['forumid'], $depth + 1)
            : '' 
        );

        eval('$forumbits .= "' . fetch_template('portal_forumsbit') . '";');
    }
    
    return $forumbits;
}

$forumbits = buildForumTree(); 


portal_forums

<table width="180" cellspacing="$stylevar[cellspacing]" cellpadding="$stylevar[cellpadding]" border="0" class="tborder">
    <tr>
        <td class="thead">Forum Tree</td>
    </tr>
$forumbits
</table>

portal_forumsbit

<if condition="$depth == 0">
    <tr>
        <td class="alt1">
            <span class="smallfont">
                <if condition="$show['collapsesubforums']">
                    <a style="float:$stylevar[right]" href="#" onclick="return toggle_collapse('forumtree_$forum[forumid]')">
                        <img id="collapseimg_forumtree_$forum[forumid]" src="images/buttons/collapse_alt_collapsed.gif" alt="Hide/Show" border="0" />
                    </a>
                <else />
                    &raquo;
                  </if>
                <strong><a href="forumdisplay.php?$session[sessionurl]f=$forum[forumid]">$forum[title]</a></strong>
            </span>
            <if condition="$show['collapsesubforums']"><div id="collapseobj_forumtree_$forum[forumid]" style="display: none"></if>
            $childForumBits
            <if condition="$show['collapsesubforums']"></div></if>
        </td>
    </tr>
<else />
    <div class="smallfont" style="margin-left: 10px; margin-top: 8px">
        <if condition="$show['collapsesubforums']">
            <a style="float:$stylevar[right]; padding-left: -13px" href="#" onclick="return toggle_collapse('forumtree_$forum[forumid]')">
                <img id="collapseimg_forumtree_$forum[forumid]" src="images/buttons/collapse_alt_collapsed.gif" alt="Hide/Show" border="0" />
            </a>
        <else />
            &raquo;&nbsp;
          </if>
        <a href="forumdisplay.php?$session[sessionurl]f=$forum[forumid]">$forum[title]</a>
        <if condition="$show['collapsesubforums']"><div id="collapseobj_forumtree_$forum[forumid]" style="display: none"></if>
        $childForumBits
        <if condition="$show['collapsesubforums']"></div></if>
    </div>
</if>