I have gotten the plugin to work but there is one major problem when you click on a result in the pop over menu it doesn't open the link !!!
heres a screen shot of the plugin so far
Spoiler
Heres the html Code used for the pop over
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<script>
(function() {
var cx = '016385124988637970925:b7wnxn09gse';
var gcse = document.createElement('script'); gcse.type = 'text/javascript'; gcse.async = true;
gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') +
'//www.google.com/cse/cse.js?cx=' + cx;
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(gcse, s);
})();
</script>
</head>
<body>
<gcse:search></gcse:search>
</body>
</html>
Heres the Extension Builder screen shot
















