<button name="id">按id排序</button>
    <button name="date">按时间排序</button>
    <ul>
        <li>
            <span name="id">123</span>
            <span name="date">2012/3/8</span>
        </li>
        <li>
            <span name="id">234</span>
            <span name="date">2012/1/5</span>
        </li>
        <li>
            <span name="id">900</span>
            <span name="date">2012/9/8</span>
        </li>
        <li>
            <span name="id">787</span>
            <span name="date">2012/2/8</span>
        </li>
    </ul>

$('button[name="id"]').click(function () {
    $('ul').html($.makeArray($('li')).sort(function (li1, li2) {
        return parseInt($(li1).find('span[name="id"]').text(), 10) - parseInt($(li2).find('span[name="id"]').text(), 10);
    }));
});