Google has recently announced an extension for Google Chrome, that lets you open Microsoft Office files directly in Google Chrome. This functionality was first seen on Chromebooks, and is likely to be a result that stems from Google's Quickoffice acquisition. Users simply need to click on links to Microsoft Office file in order to open them.
Google claims that this method of opening Microsoft Office files is not only faster, but is also more secure. That's because open files are encased in a "specialized sandbox" that prevents compromised files from interacting with your system.
If you're interested in giving it a try, just get the Chrome Beta, install the Chrome Office Viewer Beta extension, and click on a Microsoft Office Document you've stored online. Take note that this extension is still in the beta phase, and it might cause some changes in your files.
Source: Google Chrome Blog