Google Docs is the absolute worst. Keeping one open for a couple of days starts sucking up multiple GB, even for relatively simple documents.
Even if you use blank documents, the contrast is striking.
For this, honestly I'd start with something simple. So, right off, no. A script that just periodically dumps whatever ps or friends could give would be a start. If you have a suggestion on what you'll try, I can run a similar experiment on some of my computers. Warning, I don't really have easy access to MS products. :(