Do you operate a website and wish you could increase the percentage of users who finish the registration process? As discussed on Google's main blog, Google has been working with Plaxo and Facebook to improve the registration success rate for Gmail users. We now see success rates as high as 90%, compared to the 50-60% rate that most websites see with traditional registration mechanisms. This result was achieved using a combination of our OpenID, OAuth and Portable Contacts APIs. While those APIs have been available for over a year, we have added a number of refinements based on our experience with Plaxo and Facebook. Our documentation now has information on those new features, including:
OpenID User Interface Extension 1.0 (including the ability to display the favicon of the website)
x-has-session, which is an enhacement to checkid_immediate requests via the UI extension. If the request includes "openid.ui.x-has-session," it will be echoed in the response only if Google detects an authenticated session
Support for the US Government's GSA profile for OpenID