Mozilla Persona
URL = http://www.mozilla.org/en-US/persona/
Description
'Persona allows you to sign in to sites using an email address you choose. So, instead of having to manage multiple usernames and passwords across your favorite sites and devices, you’ll have more time to do the important stuff. We’ll manage the details!
Many sign-in systems carry your profile data with them; some even share that info with other sites and social networks. We believe you should control how your personal information is shared. Persona lets you get started with just your email address; you can add your profile data later, when and where you think it’s appropriate.
Persona makes things easy for site owners, too. Enabling Browser ID, the underlying Persona technology, on your site only takes a few lines of code and helps build good relationships by providing users with a trusted sign-in option. It’s a win-win!" (http://www.mozilla.org/en-US/persona/)