RankTracker based on http://cutroni.com/blog/2013/01/14/a-new-method-to-track-keyword-ranking-using-google-analytics/

ranktracker.js

(function(doc) {
  var ref = doc.referrer;
  if (ref.match(/google\./gi)) {
    var query     = ref.split('?')[1],
        keyword   = '(not provided)',
        pathname  = doc.location.pathname,
        rank      = null,
        param;
        
    if (query) {
      params = query.split('&');
      for (var i in params) {
        if (params.hasOwnProperty(i)) {
          param = params[i];
          if (param.indexOf('cd=') == 0) {
            rank = parseInt(param.substring(3));
          }
          else if (param.indexOf('q=') == 0) {
            keyword = decodeURI(param.substring(2));
          }
        }
      }
    }
    _gaq.push(['_trackEvent', 'RankTracker', keyword, pathname, rank, true]);
  }
})(document);