Mozilla Account Manager
This is brilliant, a Firefox account manager that standardises the handling of authentication on websites, including registration, login and logout handling, account cancellation, password changes, etc. It’s similar in some respects to the likes of LastPass, but it’s more focused on functionality than data, and in reality should actually be able to tie into current managers as a data store. Web application developers and major website owners need to implement this asap!
Account Manager is a prototype to dramatically simplify how you connect to sites. It implements a new protocol for websites to integrate with your browser, so you can sign in and sign out right from your toolbar. Look for the key icon, to the left of your URL bar.
(Also see the draft spec and the wiki page.)