Rated 5 out of 5 stars
We all have to deal with many, many passwords. Up until now, I have always used the same password for everything: email, credit cards, amazon, etc.
This makes it easy to do, but it is very unsafe. This addon is without exaggeration one of the most useful I have ever added to Firefox. It generates a (crazy) unique, very strong password for every website. You can specify how long, what kinds of characters to use, and whether to autologin. There are many other features that lastpass has, but those are the most important.
JUST DON'T FORGET THE MASTER PASSWORD AND EVERYTHING WILL BE FINE. The master password opens the "vault" where all your info is stored. I trust that Lastpass has taken care of securing this information.