If you're out on Saturday night and you suddenly notice all the lights go out, don't assume Con Ed shut off the power because the city fell behind on its electricity bill. Earth Hour begins at 8:30pm and the World Wildlife Fund (which is organizing the event) says participants will include billboards in Times Square, and the Chrysler and Empire State buildings. But don't think it would be a good time to go on a crime spree either. "Lighting related to public safety will remain on." [Crains]