public function authorizeUrl()
    {
        $request_token = $this->oauth('oauth/request_token', array('oauth_callback' => $this->callbackUrl));

        if ($request_token)
        {
            Session::put('oauth_token', $request_token['oauth_token']);
            Session::put('oauth_token_secret', $request_token['oauth_token_secret']);

            $url = $this->url('oauth/authorize', array('oauth_token' => $request_token['oauth_token']));
            return $url;
        }

        throw new TwitterOAuthException($request_token);
    }