Google supports 2 factor authentication for both Users and Administrators and can enforce that all the users in their domain use 2 factor authentication allowing and other organizations using Google to have 2 factor authentication for openID credentials.

Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides re-sizable compute capacity in the cloud and provides with web-scale computing. Amazon Web Services (AWS) Identity and Access Management (IAM) enables to securely control access to AWS services and resources and Multi-Factor Authentication devices to privileged users that perform system administrative functions.

RightScale cloud management enables organizations to easily deploy and manage business-critical applications across public, private, and hybrid clouds. RightScale provides efficient configuration, monitoring, automation, and governance of cloud computing infrastructure and applications.

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LastPass is an easy, secure, password solution that works across systems and browsers. Here's how explains how to take LastPass further: force saving on uncooperative sites, manage notifications, "rate" your passwords, use two-factor authentication, and more.
Facebook Connect allows over a million websites to authenticate users with Facebook profiles. However,  millions of fake Facebook profiles exist and time, money and resources are wasted on fake users. Trulioo ProfilePlus helps websites determine which registrations are legitimate so you can invest in the right customers and maximize user experience and revenues.