Google recently developed a plugin to add Google Friend Connect social features to WordPress blogs. This plugin allows your visitors to authenticate using any OpenID account such as Google, Yahoo, or AIM and then comment on your posts with no need to complete a registration form.

When a visitor authenticates as described above, a WordPress account is automatically created for them. You can later add or remove permissions for the visitor from the WordPress site administration pages. If desired, WordPress comments can be replaced by Google Friend Connect comments gadgets. In this case, no WordPress account is created, since Google Friend Connect handles both the rendering of the comments as well as comments moderation. Regardless of whether the Google Friend Connect comments gadgets are enabled or not, comment entries display the user profile picture and link to the user’s profile. In addition, a set of social gadgets are available, such as the Social Bar, Members, Recommendations, and Global Conversation gadgets. When recommendations are enabled, a "Recommend" button is displayed below your posts allowing the site members to choose the content they like most. The most popular posts will surface to the top of the list within the recommendations gadget.

The blog activities -such as posting content or commenting on a post- are submitted to the Google Friend Connect activity stream, which is visible on the social bar. All of the plugin features, as well as the color scheme, size, and labels of the social gadgets are easily configurable via admin panel, using regular WordPress admin interfaces. The plugin installation does not require any programming skills at all and you can get it at the Google Code site. To see this plugin in action visit either the WordPress with native comments demo or the WordPress with Friend Connect comments demo.

Source:http://googlesocialweb.blogspot.com/2009/10/strengthen-your-blogs-community-google.html