HTML

<div class="nav">
    <div id="navSelected" class="navSelected"></div>
    <ul id="navBd" class="clearfix">
        <li id="navCurr" class="navHover"><a href="#">网站首页</a></li>					
        <li><a href="#">网站建设</a></li>
        <li><a href="#">网站维护</a></li>
        <li><a href="#">网站改版</a></li>
        <li><a href="#">网站优化</a></li>
        <li><a href="#">成功案例</a></li>
        <li><a href="#">常见问题</a></li>
    </ul>
</div>

jQuery

//擦除效果
jQuery.extend(jQuery.easing, {
    easeOutBack: function(x, t, b, c, d, s) {
        s = s || 1.3;
        return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
    }
});

//nav初始化选中
var navCurr = $("#navCurr");
$("#navSelected").css("left", navCurr[0].offsetLeft);

//nav里的链接hover效果
$("#navBd li").hover(function() {
    if ( !! $("#navSelected").stop(true).animate({
        left: $(this)[0].offsetLeft
    },
    400, "easeOutBack")) {
        $(this).siblings().removeClass("navHover").end().addClass("navHover");
        $(this).find("a").hide().fadeIn(300);
    }

},
function() {
    $(this).removeClass("navHover");
    $("#navCurr").addClass("navHover");
    //window.setTimeout(function(){$("#navCurr").parent().addClass("navHover")},100);
    $("#navSelected").stop(true).animate({
        left: navCurr[0].offsetLeft
    },
    300, "easeOutBack");
});

})