Just came across this wonderful advanced security tool for Windows and should certainly be yet another tool in the armour for Security professionals, Network, Web and Windows Administrators and even developers to investigate their webapp or website codes.
Tamper Data is a great addon for Firefox browser more for system and network security professionals and network admins and certainly to a degree for network application developers.
McAfee Site Advisor is a security website which checks websites and rates the website if it is Secure. SiteAdvisor is been rated as one of the best sites reporting on how secure a website is.
Fortunately, there is a plugin for Firefox browser which can be installed and loads to the bottom right corner of your corner and turns Green or Red based on its security check on the website. This is of great help for users who can make sure that the website they are browsing is secure enough and should they enter any confidential information in the website they can doublecheck before doing so. Also, helpful if you ended up in Phishing websites or sites vulnerable to attacks like Cross Site Scripting (XSS)