connection.js

// Change the _open function in mongoose's connection.js to this
// and you'll be able to connect to MongoHQ URLS!

  _open: function(options){
    var self = this;
    this.db = new mongo.Db(this.name, new mongo.Server(this.uri.hostname, this.uri.port, options));
    
    if (this.uri.auth) {
      var auth = this.uri.auth.split(':');
      this.db.open(function(err) {
        if (err) return self._error("Can't connect to " + url.format(uri));
        self.db.authenticate(auth[0],auth[1], function(err) {
          if (err) return self._error("Can't authenticate to " + url.format(uri));
          if (self._close) return self.db.close();
          self._connected = true;
          for (var i in self._collections) self._collections[i].setDb(self.db);
          self.emit('open');
        });
      });

    } else {
      this.db.open(function(err){
        if (err) return self._error("Can't connect to " + url.format(uri));
        if (self._close) return self.db.close();
        self._connected = true;
        for (var i in self._collections) self._collections[i].setDb(self.db);
        self.emit('open');
      });
    }
  },