How to obtain a OpenId Identifier from Google
Solution 1:
I don't think commandlinefu supports Google OpenIDs. They need to properly add it with the method shown here. When added, a link is provided that redirects to Google's login page and uses the login process shown here:
since their site lacks this, the method cannot be used.
Support for Google OpenIDs has been requested on their uservoice.
Solution 2:
Use the following in the OpenID prompt:
https://www.google.com/accounts/o8/id
It will redirect to Google's auth service and if you are already logged in with your Google account then the login to the site using OpenID should be transparent.