Netcraft has released a rather nice little toolbar provides detail information about a website you are visiting. It also helps provide protection against phising attacks by allowing more experienced user to report it to netcraft, thus blocking any other unsuspecting users from being harmed.
 

• Clear display of sites' hosting location at all times helps you validate fraudulent urls (e.g. the main online banking site of a large US bank is unlikely to be hosted in the former Soviet Union).
• Once you report a phishing URL, it is blocked for other community members subsequently accessing it. The leverage of widely disseminated attacks (people constructing phishing attacks send literally millions of electronic mails in the expectation that some will reach customers of the bank) is utilized to expedite blocking of the fraud site.
• Natively traps cross site scripting and other suspicious urls containing characters which have no common purpose other than to deceive.
• Netcraft supervisor validation is used to contain the impact of any false reporting of urls.
• Display of browser navigational controls (toolbar & address bar) in all windows, to defend against pop up windows which attempt to hide the navigational controls to disguise location.
• Happily coexists with Google and other Toolbars.