Today at the Mix'n'Match conference, Microsoft announced a new Windows Live service that enables the sharing of data through standard web feeds such as RSS and Atom: FeedSync. The specification is now available to developers from http://www.feedsync.org/ under a Creative Commons License.
Previously known as Simple Sharing Extensions (or SSE), the specification has evolved, from an idea first put forward by Ray Ozzie, through discussions between Microsoft and the SSE online community. What makes the FeedSync specification useful is that it as well as enabling data inputs from multiple devices/locations at the same time, it is designed to resolve any conflicts that may come about as a result.
For example, imagine if Windows Live Calendar beta offered FeedSync capabilities. Users would then be able to subscribe to their own RSS feed, and if they so wished, ammend appointments simply by editing the feed. Of course this would require a FeedSync client, something not yet available, but it would seem like a good use of the technology.
For those wishing to test out SSE, you can do so over at Live Labs.FeedSync, Live Labs, PhotoZoom, Silverlight, Streaming, Windows Live, Feeds, Microsoft, Launch