works great -- but Rated 5 out of 5 stars
First you'll need a working DNS server. Almost NO DNS servers out there support DNSSEC yet. This include's Google's public DNS it seems. (For shame Google!) Once you have it installed, right click the key that appears next to your address bar, click on Preferences, and choose another DNS that actually supports DNSSEC. Then you'll have to find a site to actually test it against. Almost no sites have DNSSEC records yet. This includes facebook, google, etc. FOR SHAME. If you'd actually like to test to make sure this tool is working, try http://www.verisign.com/ (You should get a green key.) I'd love for this support to be embedded into Mozilla and not depend upon some unknown (to me) author's add-on.