"The Mozilla Labs Design Challenge is a series of eventsto encourage innovation and experimentation in user interface design for the Web." (link)
Like I've said before Weave is a great Firefox extension that syncs your browser data (that includes, bookmarks, history, cookies, passwords, form auto-completions, tabs, preferences, extensions and more in the future) across all your browsers: On your desktop PC, laptop or mobile.
So anyway, Mozilla set a project for letting the users help out on suggesting ideas for the Weave Web UI. Here's mine.
I'm not that good with UI but I know what I want; The problem with the auto-completion of passwords is that you forget them rather quickly when you don't need to type them anymore! So providing a "forgetful" mode for a login sounds good. If you could mark a password for a reminder every now and then you probably won't have to dig through your mail looking for that activation mail from your website or to reset a password when you're using another computer without Weave installed.
Now for the web UI. I don't know if this will / should be the final design, simply because I don't know what will be comfortable. But still, here's what I had in mind for the Weave Passwords Web UI:
To create these I used Balsamiq Mockups: http://www.balsamiq.com/demos/mockups/Mockups.html