One of the methods of phishing your personal information is to direct you to a spoofed site, that looks exactly how it's supposed to, but the appearance is just a trick to lead you to a site designed specifically to collect your personal info. Firefox released an add-on that will help identify sites that have been spoofed – it's Locationbar².
What it basically does is helping casual computer users to identify fake sites and detect phishing scam. It linkifies URL segments, hides protocol names, decodes URL for better readability and puts emphasis on the domain, reducing spoofing risk.
A lot of phishing scams use the name of the site you intended to enter as a sub-domain name which pre-pends the real-fake domain name, so the user can be easily misled, while not paying attention to his address bar. Locationbar² helps you prevent that.