mechanize:Mechanize::File#filename
>> require 'mechanize' => true >> agent = Mechanize.new => #<Mechanize:0xb74cc234 ... >> agent.get('http://www.google.co.jp/intl/en_com/images/srpr/logo1w.png').class => Mechanize::File >> agent.get('http://www.google.co.jp/intl/en_com/images/srpr/logo1w.png').filename => "logo1w.png"