Last Saturday, March 26, people and businesses around the world participated in Earth Hour 2011, turning off their lights at 8:30 p.m. local time. Earth Hour was organized by the World Wildlife Fund in 2007, as a way to bring attention to energy-consumption, sustainability, and climate change issues. This year, participants in 134 countries darkened homes, skyscrapers, and landmarks around the world. The images below (starting with photo number two) are interactive -- click on each image to "turn off the lights" (For wider screens, be sure to click the "1280px" option at right.)