Google has just launched Google Friend Connect
http://www.google.com/friendconnect/home/moreinfo
Google Friend Connect is in preview stage and is being tested by some web sites. It enables web site owners to add social features to their web sites (such as message boards/member management/photo-sharing/ratings and review facilities). Some of these social features (or rather what Google likes to call social gadgets) have been either developed by Google or outside developers. This is a highly significant development as Google friend connect will enable web sites to easily add in their Facebook friends. The web is becoming more open and the 'walled garden' approach of social networks is now dead. It will remove the need to join multiple social networks and people will be able to link up with their friends all across the web rather than where they first registered their details. In effect people will be able to plug their social network into other sites. Google is marketing Friend Connect as a means for site owners to increase traffic (which can grow virally through the addition of social features) and of enrichening sites through the addition of social features.
From a marketing perspective, Google Friend Connect presents an excellent opportunity for brands to develop social networks of their own, adding features they think will work best to their sites, blogs or microsites. In terms of the power struggle on the web, this is a masterly stroke by Google to lead the social media growth online. From an advertisers' perspective, it will be interesting to see how Google offers ads through Friend Connect. That though could be difficult as Facebook has discovered.