Sydney's iconic Harbour Bridge and Opera House will help kick off the energy-saving marathon, with Egypt's Pyramids and Sphinx, the Trevi Fountain and Tower of Pisa in Italy and all major landmarks in Paris to take part, led by a five-minute blackout of the Eiffel Tower. The Forbidden City in rapidly developing China, which was blamed by many activists for Copenhagen's failure, will go dark, along with the “Bird's Nest” Olympic stadium. And in Dubai, the world's tallest skyscraper, the Burj Khalifa tower, will also dim its lights. __