Plugging into the big SNS sites
All at the same time, Facebook, Myspace and Google have released API’s that let third party websites access social network data like friends lists, profile data, status info etc. This will pave the way for apps that allow you to co-ordinate social activity across multiple sites.
The three API are “Friends Connect” from Google, which hooks into Open Social, “Facebook Connect” and “Data Availablity” from MySpace.
You can read more on in this TechCruch article.