In the past I have used WOT add_on for trusted sites. With NIS 2012 it includes a toolbar with Safe Web, a rating system from Norton. In the past Norton has made available Safe Web Lite a free toolbar Norton Safe Web, from Symantec - Safe Websites | Norton Safe Web Lite
but I have heard it does not work with FF 9 or 10. I just learned Norton has released a beta version of its replacement called Identity Safe https://identitysafe-beta.norton.com/
which has the same features that come with NIS 2012. It has the Safe Web and includes Identity Safe which is a password manager and fills in your login information for your sites. Take a look and give it a try.