The document discusses the development of Activity Streams, a format for expressing activities like status updates, photos, and bookmarks across different social media sites. It proposes using a common format of "actor verb object" to describe activities. For example, "Chris posted a photo" or "Sarah bookmarked a website." The benefits listed include staying connected to friends across different sites, an open ecosystem for apps to access activities, and tools for filtering and analyzing activities. The document also provides examples of early Activity Streams implementations and outlines ongoing work to develop an open standard format using ATOM and other technologies.