I have been using the free web app versions of Microsoft Office (Word, Excel, Powerpoint) for a while now which work quite well in my PB's browser.Has helped when i needed a bit more functionality than the built in stuff while on the go...especially to make changes to a Powerpoint file before a presentation.
To use, go to skydrive.live.com and click on the 'PC Site' link at the bottom of the landing page to get to the fully functional site.