    # File lib/plugins/growl.rb, line 68
    def get_icon_path(s)
      Dir.mkdir_p(config.plugins.growl.icon_cache_dir) unless File.exists?(config.plugins.growl.icon_cache_dir)
      cache_file = "%s/%s%s" % [  config.plugins.growl.icon_cache_dir,
                                  s.user.screen_name,
                                  File.extname(s.user.profile_image_url)  ]
      if !File.exist?(cache_file) || (File.atime(cache_file) + 24*60*60) < Time.now
        File.open(cache_file, "wb") do |f|
          begin
            f << open(URI.escape(s.user.profile_image_url)).read
          rescue OpenURI::HTTPError
            return nil
          end
        end
      end
      cache_file
    end