download_all_railscasts.rb

    require 'hpricot'
    require 'open-uri'
    railscasts_path = File.join(Rails.root, 'tmp', 'railscasts')
    FileUtils.mkdir_p(railscasts_path)
    feed = Hpricot(open("http://feeds.feedburner.com/railscasts"))
    feed.search('enclosure') do |enclosure|
      puts "Downloading: #{enclosure[:url]}"
      `cd #{railscasts_path} && wget #{enclosure[:url]}`
    end