You like trivia questions, right? Here’s one for ya: What do Coldplay, Archbishop Desmond Tutu, Edward Norton, Wynonna Judd, Cate Blanchett, and Captivate-enabled buildings all have in common?

I’ll give you a hint: March 28.

Still don’t have it? OK, I’ll end your anguish (for those of you who might've missed the headline or the movie above, anyway): They’re all participating in Earth Hour, the World Wildlife Fund’s annual lights-out event that aims “to make a global statement of concern about climate change and to demonstrate commitment to finding solutions.”

And you too can join in the rarefied celebrity/news-monitor-equipped building ranks by signing up at the Earth Hour website. It’s simple to live up to the commitment: You just turn off your lights – all nonessential electricity, actually – for one little hour, from 8:30-9:30p (local times). So join the likes of the Acropolis in Athens; the Sphinx and Great Pyramids of Giza; and Broadway, and live without those lights for one hour.

And find out if your Captivate-enabled building is participating by checking out the Earth Hour map.