Thanks for all of your replies. I didn't know that tools such as tracker would search with openoffice document.
With respect to the command line, I have fixed on find . -name *.odt -exec sh -c 'unzip -c "{}" content.xml | grep "string-being sought" > /dev/null' \; -print but it returns immediately, and seems to do no searching. To my amateur eyes, it looks like it should work. I've done some searching, but to no avail. Anybody got ideas? John