get.js

// Ajax Get. Cached. And aborts current request
var get = (function($) {
  var xhr;
  var xhrURL;
  var cache = {};
  return function(url, callback, jsonp) {
    url += ((url.indexOf('?') === -1) ? '?' : '&');
    url += jsonp ? 'callback=?' : 'ajax=1';
    if (url == xhrURL && xhr.readystate != 4) {
      // Already loading stuff, wait for it to finish
      return;
    }
    if(xhr && xhr.readystate != 4){
      xhr.abort();
    }
    xhrURL = url;
    
    if (cache.hasOwnProperty(url)) {
      callback(false, cache[url]);
      return;
    }
    xhr = $.get(url, function(data) {
      cache[url] = data;
      callback(false, data);
    }).error(function(e) { 
      callback(e);
    });
  };
})(jQuery);