Append content on random location with jQuery?
<ul class="itemlist">
    <li>Item #2</li>
    <li>Item #2</li>
    <li>Item #3</li>
    <li>Item #4</li>
</ul>

.itemlist li{
    width:100px;
    height: 100px;
    margin: 8px;
    padding: 4px;
    float: left;
    background: #dddddd;
}

var $lis = $(".itemlist li");
$lis.eq(Math.floor(Math.random()*$lis.length)).after(
                                            /* your new content here */ );

var randomNum = Math.floor(Math.random()*9);
$(".itemlist li").eq(randomNum).append("HI");