(via David Recordon)
Once you’ve logged in to your Google account, you just use:
On any site which relies on OpenID for validation.
So now Yahoo!, AOL, and Google have (direct or indirect) mechanisms for providing OpenID (and Microsoft has committed to doing so in the future).
Combined with all the free, purpose-built OpenID providers (like ClaimID, MyID, MyOpenID, MyVidoop, and Clickpass) and it looks like 2008 could be the tipping point (assuming one hasn’t already occured in 2007).
(See OpenID Status Check for a recent, and more exhaustive list).