Big surprise, who (or what) isn't on Facebook these days? If you would like to connect with other Earth Hour participants, there are several groups devoted to the global event on the social networking site. By joining one of these groups you can post articles related to Earth Hour, discuss hot topics with other members and post photos or notes regarding the activities you are planning or particpating in.

You can also download the Zero Footprint calculator (and invite friends to the same), where aspects of your lifestyle - including your car and the amount you drive it, eating habits and travel patterns - are assessed to measure your environmental impact. You are also given the option to offset your footprint and sign up for Eath Hour through the application.

Hit the jump to add the calculator to your Facebook profile and begin connecting with other individuals who will be switching off their lights this Saturday evening.

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