You tend to hear more about OpenID, but OAuth has its own loyal following using the protocol for authentication. OAuth has been implemented by organizations like Flickr and Netflix - and has been promised to be in the works for Twitter. Combining OAuth with OpenID offers an improved user experience by letting each technology do what it does best. The benefits of this technique are demonstrated by registering for a new Plaxo account using your Google account.

How It Works

The "hybrid approach" - currently available in a limited beta - that Google and Plaxo have employed uses OpenID to sign in, then invokes OAuth for delegated authorization, and finally calls on the Google Contacts API to access information about contacts. And it does all of this transparently to the end user.

The first step in the Plaxo-Google scenario involves a new user being invited to Plaxo by a friend via Gmail. The invite understands the user is logged into the Google system and prompts the recipient with a "Sign up with my Google Account" button.

After clicking the button, the new user is directed to a Google Accounts page and asked to confirm their identity. The user is also given the option of allowing Plaxo to remember him or her in the future.

Accepting the sign-in request allows Plaxo to have access to the user's Google account credentials and the contacts associated with that account. The end result? The user now has a Plaxo account without all the rigamarole generally associated with a new account setup - and without a new username and password to track.

Why This Matters

While the concept of site-specific logins made sense in the early days of the Web, the idea of users being forced to develop a new identity, username, password, and profile on every site they visit - including adding all the same people as connections, over and over again - seems almost laughable today. It's definitely not scalable. Especially as password requirements become more and more stringent.

With the launch of Facebook Connect, the idea of a digital identity that could follow users from site to site moved from bleeding-edge tech people to a much larger contingent of the general populous. And the ease-of-use demonstrated by Facebook Connect put some friendly pressure on the OpenID contingent to improve the way they were managing the login process.

Plaxo's and Google's demonstration is something that could improve usability for all OpenID logins, reducing the series of handoffs that tend to frustrate and confuse users. But as Eric Eldon of VentureBeat notes, there is still more to be done:

"Multi-site sign on, like what the companies are announcing today, will be more compelling when it can bring integration down to one or zero clicks, but this is certainly a step in the right direction."

Who Wins? Everyone

This isn't a "winner takes all" pursuit or an "either/or" situation. We are participating in a Web environment where both Facebook Connect and OpenID can co-exist, because there are different applications that make both options viable and useful.

Personally, I'm not likely to use my Facebook account to access my bank and credit card accounts. But I am likely to use my Facebook credentials for social sites that would be enhanced by my existing Facebook connections. Similarly, my OpenID isn't always the right answer.

Facebook has momentum and a fervent user base. OpenID has a who's who of tech companies getting behind the concept as the preferred way to manage digital identities. Neither of these identity options are going away anytime soon.

What's best about the current situation is the rivalry between the two camps: one proprietary and easy-to-use, one open and more complex. It will be interesting to watch the two solutions push one another to become more and more simple for the end user. Because in that case, we all win.