Something

// PRIMARY LINKS
$pid = variable_get('menu_primary_menu', 0);
$items = array();
$items[] = array(
  'pid' => $pid,
  'path' => 'blog',
);
$items[] = array(
  'pid' => $pid,
  'path' => 'event',
);
$items[] = array(
  'pid' => $pid,
  'path' => 'profile',
);
$items[] = array(
  'pid' => $pid,
  'path' => 'og',
);
foreach ($items as $item) {
  menu_save_item($item);
}