This lil Ruby-OSA script will allow you to import your "Flagged Items" in NetNewsWire as Web Archive Items in Yojimbo. Thus allowing you to save RSS articles for off-line viewing/storage.
['rubygems', 'rbosa'].each {|lib| require lib}
nnw = OSA.app('NetNewsWire')
yojimbo = OSA.app('Yojimbo')
nnw.subscriptions.find { |s| s if s.display_name == 'Flagged Items' }.headlines.each do |article|
unless yojimbo.web_archive_items.map { |f| f.source_url }.include?(article.url)
archived = yojimbo.make(OSA::Yojimbo::WebArchiveItem,
article.url,
:name => article.title)
sleep(5)
end
end