OpenID was created to solve one of the Web's biggest annoyances: log-ins. You've already got a verified identity on one site, so why do you need one for every place you visit? With OpenID, site owners can simply built it into their Web apps and services, letting you use your verified credentials from one site in place of having to sign up for yet another log-in.
The hope of OpenID is that it becomes a standard and universal system across every site, letting new sites spring up and have users more comfortable with signing up with less hassle. As of right now, there are nearly 10,000 sites that support OpenID, and many large and popular companies are adding OpenID as an option for new user registration.
Winner: OpenID (OpenID.net)