Facebook Supports OpenID as a Relying Party

Here's how it works:

1. Login to your Facebook account normally, go to Settings/Account Settings/Linked Accounts, and link your Google, Yahoo, MySpace, Vidoop (whatever it is), Myopenid, or a generic OpenID account like VeriSign PIP.
2. Grant the permissions as needed.
3. Log out of your Facebook account.
4. Log in to your primary account such as Google.
5. Navigate to Facebook - after a short delay you will be redirected to your Facebook Home!
   

Sweet.