i've been hacking OO-files for a while, and one useful tool have been ant. Using ant-tasks to unzip, transform content.xml, manipulating resourcefiles etc., and then zip the result, speeds the process.
I'm doing something similar. I write all my blog articles in Open Office. An ant scripts scans the article directory, builds a list of OO files, collates it, and uses XSLT to build index pages and individual article pages.
Do you have an example somewhere online or can you post more details here about how you do that? I'm particularly interested in how you might run XSLT transformations on the content of a document.