"OpenID is an open decentralized digital identity system that
has been gaining traction in recent months. It implements a
solution to some everyday headaches such as single-sign-on, but it
does not address related issues like privacy, trust, spam
prevention, or message authentication. OpenID uses a multiple-stage
sign-on process, but don't let that discourage you. As an end user,
the benefits are stacked in your favor.
"As the most basic level, your OpenID identity is a unique URL.
It can be a URL that you directly control (such as that of your
personal Web page or blog) or one provided to you by a third-party
service, such as an OpenID provider. In that sense, a site's use of
OpenID identities is no different than using email addresses as
identifiers: they are unique to each user and are verifiable. But
you can publicly display an OpenID identity without attracting