Firefox: It's not just Facebook that's actively tracking your movements on the web without your consent. If you want to use those services when you want without trading your privacy for the privilege, Priv3 is a Firefox extension that gives you back the ability to choose.
Priv3 is the result of researchers at Rutgers University and the University of California at Berkeley. The extension doesn't completely block all third-party data transactions, but what it does is selectively stop social services like Facebook, Google (specifically Google's +1 button,) Twitter and LinkedIn from dropping their tracking cookies on your computer and reading them when you're on other sites.
That means you can use all of those services, but you don't have to worry that every site with a Facebook Like button is transmitting your information: the extension. If you do decide to click the +1 button or the Like button, the extension will reload your session cookies and let the interaction through. In essence, it gives you the ability to opt out of the tracking unless you specifically opt-in by clicking to share with your friends. Thanks SammySoul!
Priv3: Practical Third-Party Privacy [University of California: Berkeley]