jQR is a jQuery plugin generates QR-Codes without calling external urls. It's entirely written in Javascript
<div id="qrcode"></div>
<script language="javascript">
$(document).ready(function() {
$('#qrcode').qrcode("Hello World");
});
</script>
Currently, jQR generates too big QR-Codes, therefor, it's only usefull for small amounts of data. I'm hoping to get this fixed.