Open Id

OpenIDs are universal login names that can be used across any OpenID-enabled website, resembling domain names like example.com/bill. Developed by Brad Fitzpatrick for blogging needs in 2004, OpenID launched a $50,000 bounty program in 2006 and now has over 160 million users and 10,000 supporting sites. OpenID allows for a single sign-on across multiple sites without ownership by any single entity and is supported by companies like AOL, Yahoo, and Google.