Zara, the fashion store, with fabulous European styled clothes, has posted their support of Earth Hour on their website: http://www.zara.com/. I also spotted Google's support on http://www.google/.com.
WWF is hoping to bring in a billion"votes" in the form of lights being turned off between 8:30 and 9:30 p.m. The votes will be presented to world leaders at the Global Climate Change Conference in Copenhagen 2009.
Google has also posted tips on how to power down you computers.
check out: http://www.earthhour.org/, or the Zara or Google websites.