While Google's involved in the OpenID community's efforts, even though it doesn't yet supported the usage of OpenID standard for replacing passwords on its own sites.
Google've now announced using of OpenID for the Google signup process. "Currently, Google only offers this feature for Yahoo! users, who sign up with Google see the page (pic1) with a button, when you click the button, it send you to Yahoo! for verification page. Clicking on the consent button 'Agree' to share your email address with Google, you're done and can start using any Google service, such as Google Groups, Docs, Reader, AdWords, etc.," informs Google.
"We plan to use it in future with other email providers that add support for OpenID and related standards like OAuth, such as in Microsoft Live identity APIs. Other websites that need to verify a user's email address can also implement this technique using Yahoo!'s OpenID API," added Google.