[Dismounted]

MySQL will automatically sort by the primary key if no order clause is specified in a query. Dirty way is below, I can't think of anything else off the top of my head.

PHP Code:

$menuids = '5,10,3,1,4,7';
$menus = $vbulletin->db->query_read("
    SELECT id, shortdescription
    FROM " . TABLE_PREFIX . "menus
    WHERE id IN ($menuids)
");

$menus_temp = array();
while ($menu = $vbulletin->db->fetch_array($menus))
{
    $menus_temp[$menu[$id]] = $menu;
}

$menus_array = array();
$id_order = explode(',', $menuids);

foreach ($id_order AS $id)
{
    $menus_array[] = $menus_temp[$id];
}