I have used NoDofollow add-on for Firefox for a long time now. It is actually my favourite Firefox addon, just a little one effective enough to show you dofollow and nofollow links. But as I upgraded Firefox to latest version 3.6 some days ago, I found NoDofollow is not woking with it. So I waited and waited for the original developer to make an update to support it for latest Firefox. But it hasn’t happened yet. But today I found an unofficial version of NoDofollow that supports Firefox 3.6. You can find it in Scott Miller’s blog. I tested it personally in my Firefox 3.6 and it is working perfectly.