http://blog.darkhax.com/2009/05/24/rss-fun-with-feedzirra

feedzirra-example.rb

feed.entries.each do |e|
  "Looking at the entry #{e.title.gsub("n",' ')}".printn
  link = (Nokogiri(e.summary)/"img").to_html
  next if link.empty?
  link = link[/"(.*)"/].gsub(/["]/,'')
  filename = link.split('/').last
  disk_file = File.expand_path(File.join(ROOT,filename))
  unless File.exists?(disk_file)
    "Downloading new image #{filename}...".print
    Net.download_and_save(link,disk_file)
    "done!".printn
  end
end