Lookit there, Google is what Passport wished it'd become.

Why Google Checkout?:

Google Checkout is a checkout process that you integrate with your website, enabling your customers to buy from you quickly and securely, using a single username and password. And once they do, you can use Checkout to charge their credit cards, process their orders, and receive payment in your bank account.

Makes me wonder if the viruses on Windows didn't cost it the ability to become the first Google, so to speak. People simply didn't trust Passport, afaict. Now Google is all about trust. Whether it should still be considered that way is a question for another day.