You may not know this, but the creator of LiveJournal, Brad Fitzpatrick, also created a de-centralised authentication system called OpenID. Today, it was announced that Microsoft, IBM, Google and Yahoo have joined the board of the OpenID Foundation meaning that users could have just a single sign-on for multiple websites.
On a personal note, I hope that this really pays off for Brad. He has created at least two highly-innovative concepts that have really kicked off recently. I hope he gets full and proper credit for it.