Master password in Firefox, not in Safari!
Firefox has a useful feature that doesn't seem to be available in Safari. It is the master password. It offers an additional level of protection if you choose to have Firefox save your passwords. Having your browser save passwords can be risky if someone gets access to your Mac. If you set a master password, Firefox will ask you for your master password at every session where you want to log in with a saved password. The advantage is of course that one password is a lot easier to remember. You can set the master password in the Security tab.