function foo_menu_item($mid, $children = '', $leaf = TRUE) {
    $item = menu_get_item($mid);
    $id = 'menu-' . strtolower(preg_replace("/[^A-Za-z0-9]+/", "-", $item['title']));

    if ($item['weight'] == 10) {$class = 'lastlink';}
    if ($item['weight'] == -10) {$class = 'firstlink';}
    $label = menu_item_link($mid);
    return '<li id="' . $id . '" class="' . $class . ' ' . ($leaf ? 'leaf' : ($children ? 'expanded' : 'collapsed')) . '">' . $label . $children . "</li>";
}