OK, I searched this question on SO but no good answer. After spent some time I figured out how to do it. I'm going to answer this myself as a way to share it.
+39
A:
Now it is possible delegate OpenID to your Google account (not Google Apps).
No, this is not using the demo OpenID provider using App Engine. This is your REAL Google account!
First you need to enable your Google Profiles. Try to view your profile and edit it, there should be an option to set your Profile URL. You have two choices there: either use your Gmail account name (without the @gmail.com part) as your profile id, or a random number assigned to you. It's up to you to decide which one to use. Either way, that id is your profile id below.
Now add the following HTML code to your delegating page:
<link rel="openid2.provider" href="https://www.google.com/accounts/o8/ud?source=profiles" >
<link rel="openid2.local_id" href="http://www.google.com/profiles/[YOUR PROFILE ID]" >
And it's done. Now try login SO with your custom url!
Rio
2010-03-30 12:50:25
What does the local_id line do? What if I wanted to enable multiple OpenIDs on my own domain name? These <link> tags have to go only on a single URL that I use as my OpenID, right?
Eric Falsken
2010-06-18 18:58:44
I assume you would need to add multiple <link rel="openid2.local_id" ...> tag to your page if you want to use multiple OpenID. Haven't tried myself, but I think it's the right direction.
Rio
2010-10-15 05:02:25