code: def generate_authorize_url(request_token)
        request = consumer.create_signed_request(:get,
          consumer.authorize_path, request_token,
          {:oauth_callback => 'oob'})
  
        params = request['Authorization'].sub(/^OAuth\s+/, '').split(/,\s+/).map do |param|
          key, value = param.split('=')
          value =~ /"(.*?)"/
          "#{key}=#{CGI::escape($1)}"
        end.join('&')
  
        "#{base_url}#{request.path}?#{params}"
      end
docs: copied from t, the awesome twitter cli app
   @see https://github.com/sferik/t/blob/master/lib/t/authorizable.rb