Microsoft Office Live Workspace is Microsoft's tool for sharing Office documents and mission critical files between multiple users. Workspace users can select privacy controls for each document and get the heads up when another user is editing it. If they want to work on a shared document at the same time, Live Workspace also taps into Microsoft's SharedView to enable screen sharing and overwriting protection.
In addition the Web view, users can take advantage of a plug-in for Microsoft Office that links up to Live Workspace, letting them save documents in real time to their selected Workspace without even having to navigate to the site.
Live Workspace will eventually include Web-based versions of Microsoft's Office apps, which should be released around the same time as this year's software version of Office. As it stands, clicking on one of your stored files will fire up that software application.