Google Docs is now providing offline access to editing files on an experimental basis. As of now, this only works with Docs, rather than Spreadsheets and Presentations, but it is definitely a start in a direction that may have far-reaching results in the way we all use computing.
ChannelWeb provides opinions from many users about this new feature that works on Google Gears, an open source browser extension that enables web applications to provide offline functionality.
Even with Docs, this option has not been made available to all Google accounts, so if you don’t see this functionality yet, you might have to wait a little while longer. I’m waiting to see how Google implements this technology into the Presentations component of Google Docs. And while many sites and bloggers seem to indicate that this might be a big blow to Microsoft Office, I think there’s so much more to wait and watch before making a blanket statement of that magnitude.