Firefox only: Create strong passwords with Password Hasher, a Firefox extension that automatically generates unique passwords based on the destination. Unlike previously mentioned PwdHash, Password Hasher has integrated functionality (the “Bump” button) that assigns version numbers to passwords. It also consolidates passwords for domains, which is particularly useful if you use the same login across several subdomains on the same main site. Finally, save portable versions of the HTML so that you can generate your hash words on any machine without requiring the Password Hasher extension itself. Password Hasher is a free download, works wherever Firefox does.
Password Hasher [Firefox Add-ons]

Nice program if you are concerned with online passwords!! Only use this if you intend to keep your password file backuped!!