OpenSocial integration

OpenSocial provides a common set of APIs for social applications across multiple websites. Using standard JavaScript and HTML, they enable developers to create apps that access a social network's friends and update feeds.
Common APIs mean you have less to learn to build for multiple websites. OpenSocial is being developed by Google in conjunction with members of the web community. The ultimate goal is for any social website to be able to implement the APIs and host 3rd party social applications.

http://code.google.com/apis/opensocial/