Useful macro that saves a copy of a document to plain .txt file (works for Writer and Calc documents, autodetects their MIME type and chooses appropriate export filter: CSV for Calc sheets, plain text for Writer documents).
Just assign it to your document's "Document has been saved" event (Tools->Configure, Events tab) and you'll have an automatically maintained plain text version of that document. Very handy when you frequently have to look up something quickly in that document, but have no time to launch OpenOffice (you know it starts up for ages ;) )