Mozilla Account Manager
The Mozilla Account Manager project aims to simplify the login connection process to websites and services by implementing a new protocol "that sites can use to define their account-and-session management features" that integrates with the web browser.
The Account Manager is described as an evolution of the password manager that is integrated in Firefox and the identity components used in Weave. What it actually will do is allow users to manage their logins and profiles for each website.
The Account Manager is provided as a prototype add-on that can be downloaded from the project's homepage over at Mozilla Labs.
It displays a new key icon in the Firefox address bar by default which can be clicked on to access the functionality provided.
The prototype works only on a few sites currently including Google, Yahoo, Facebook, Mozilla Add-Ons, Mozilla Bugzilla and Personas. Saved login information need to be available in the Firefox password manager as well for it to function.
Several features are currently in the making: this includes global profiles, automatic website registrations using the global profile, a detailed account viewer, and auto login support for configured services and websites.
This sounds a lot like the functionality of password managers like Last Pass. There is a striking resemblance when the features are compared. The main difference between a password manager and the Account Manager is the Account Manager's requirement that websites and services implement the draft specs (and later specs).
This alone makes it unlikely that the majority of websites will implement that feature.
Interested users can visit the Mozilla Labs page that contains information and downloads, take a look at the draft document or visit the Mozilla Wiki page for additional information and status information. (via Techie Buzz)
Update: Mozilla Account Manager is no longer available. Part of it seems to have found its way into BrowserID which Mozilla announced in 2011.
Update 2: Mozilla turned BrowserID into Mozilla Persona.
Update 3: Mozilla announced that it will shut down Personal on November 30, 2016.