oneDrum released a peer-to-peer desktop application to enable collaboration within Microsoft Office applications:

“Inspired by the concept of a networked application that could reduce the cost and friction associated with true collaboration, oneDrum was developed to respond to the needs of the modern, mobile information worker. The application brings Google Docs functionality and more to Microsoft Office documents, with edits appearing in real time when working online, while offline edits synchronize effortlessly when connectivity is re-established.

Allowing users to work in their native Microsoft Office application environment, oneDrum takes the compromise out of collaboration and is the only application that lets users have shared documents on hand, and up to date, at every moment. This all takes place using a simple and complete security model that combines user authentication, network security and data encryption to ensure that all aspects of the collaboration process are secure.“

There’s a version available immediately for Windows, and a Mac edition with support for Office for Mac is due before the end of June 2012.

I couldn’t find a screenshot on the oneDrum website. Some are needed, IMO.