I don’t know about you, but I did this. I went through my site and added a bunch of XFN. I had run rel‘ing away. It didn’t really do much for me though, it was always a promise of an open format. I played with a few tools, but I largely forgot about it. When I add a friend in Facebook, or Twitter, or …. I see immediate effect.
I am really hopeful that the Google Social Graph API and other efforts change the equation though. This is only the beginning, so who knows where it will go!
The new Social Graph API makes information about the public connections between people on the Web easily available and useful. You can make it easy for users to bring their existing social connections into a new website and as a result, users will spend less time rebuilding their social networks and more time giving your app the love it deserves.
Here’s how it works: we crawl the Web to find publicly declared relationships between people’s accounts, just like Google crawls the Web for links between pages. But instead of returning links to HTML documents, the API returns JSON data structures representing the social relationships we discovered from all the XFN and FOAF. When a user signs up for your app, you can use the API to remind them who they’ve said they’re friends with on other sites and ask them if they want to be friends on your new site.
This is exciting to me as:
It actually uses the microformat standards such as XFN