yql_grab.js

// Scrape/Grab page using YQL via JSONP
function grab(url, cb) {
  var fn = '__grabber' + +new Date;
  var query = 'select * from html where url="{URL}" and xpath="*"';
  var yurl = 'http' + (/^https/.test(location.protocol)?'s':'') + '://query.yahooapis.com/v1/public/yql?';
  yurl += [
    'callback=' + fn,
    'format=xml',
    'q=' + encodeURIComponent(query.replace('{URL}', url))
  ].join('&');
  window[fn] = function(d) {
    delete window[fn];
    document.body.removeChild(script);
    var div = document.createElement('div');
    div.innerHTML = d.results[0];
    cb(div);
  };
  var script = document.body.appendChild(document.createElement('script'));
  script.src = yurl;
}

grab('http://yahoo.com', function(div) {
    console.log(div.querySelector('title').textContent);
});