wrap 3 divs in a div
http://stackoverflow.com/questions/3366529/wrap-every-3-divs-in-a-div
by Joseph Tate
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<div class="category">Content</div>
<div class="category">Content</div>
<div class="category">Content</div>
<div class="category">Content</div>
<div class="category">Content</div>
<div class="category">Content</div>
CSS
.new {
border: solid 1px #FF0000;
padding: 1em;
margin:1em;
}
JavaScript
var divs = $("div.category");
for (var i = 0; i < divs.length; i+=3) {
divs.slice(i, i+3).wrapAll("<div class='new'></div>");
}