The Social Graph API is a major step in the development of what I’ve called “the Internet Operating System.” In a nutshell, what the Social Graph API does is to lower the barrier to re-use of information that people publish about themselves on the web.

Enter a buch of URLs that are yours: blogs, Twitter etc. The API returns a list of sites that it infers are mine, either because I’ve linked to them in a way that indicates they are, or because someone else has done so.