This week Mozilla Labs announced that their Account Manager tool is moving from the lab to be included in a future Firefox release.
"The Account Manager makes it incredibly easy for users to create new accounts with optional randomly generated passwords, and log into and out of them with just a click. As a web developer, adding support for this feature could take as little as fifteen minutes of hacking," the announcement said.
Basically the point of Account Manager is to make it easier for Firefox users to log into Web sites.
To learn more about Account Manager, you can read the draft specification. To join in on the discussion about Account Manager, you can check out the discussion group. On May 20, Mozilla is holding an in-person meet-up.