For example, someone could use an existing account on these sites to register and sign in to other Web sites. That way, people don't have to create an account for every Web site that requires one, reducing the number of log-in details they need to remember.
These data portability programs also aim to let people port to other Web sites content they have loaded onto their existing accounts, like profile information, photos, notes, list of contacts, comments, status updates and the like.
"It's all built on the idea of providing our users with a way to make their personal identity more portable around the social Web and doing it in a way that emphasizes privacy for the user. It's about making a user-centric identity platform," said Engel.
While few can argue with the broad goal of data portability, the road towards broad data portability is long; thorny technology, business and privacy issues need to be worked out and solutions agreed upon industry-wide.
For example, days after the initial announcements of their data portability programs in May, Google and Facebook promptly locked horns. Facebook blocked Google's Friend Connect service from accessing Facebook members' data, saying the Google program violates its terms of services because it redistributes Facebook user information to developers without users' knowledge.
The impasse remains. Last week, seemingly to underscore how competitively important their respective data portability efforts are, Google and Facebook separately announced on the same day that they were opening up their programs more broadly.
MySpace's decision to mesh its MySpaceID with Friend Connect isn't surprising, considering the companies' collaboration on OpenSocial, a project Google launched to come up with a common set of APIs for social networking applications. OpenSocial hasn't been adopted by Facebook. Many consider OpenSocial a threat to Facebook's application development program for external programmers. Facebook's program was first out of the gate and is considered the front-runner.
MySpaceID has so far been implemented by AOL, Flock, Eventful and Flixster, among others. New MySpaceID partners announced Monday include Vodafone and Netvibes.
With Friend Connect, MySpaceID will be driven to a "long tail" of smaller Web sites that adopt the Google program to add social networking features to their sites, Engel said.
Engel points out that MySpace is prioritizing the use of open standards in its effort, such as the OpenID framework for single sign-on, the OAuth protocol for authentication and OpenSocial, which Google spun off into an industry initiative led by a non-profit foundation.
Developers who have already done work with MySpaceID, which was announced in May, will not have to rewrite code to take advantage of the new features coming to it.
Participating in MySpaceID is an option to members of the social networking site. Those who opt in can manage the various MySpaceID capabilities from a central console in their account.