Lights Out!

Neat pictures! More than 1,000 cities in over 80 countries observed Earth Hour 2009 on Saturday March 28th, as homes, office towers and landmarks turned off their lights for an hour starting at 8.30 pm local time.
Collected here are a series of before-and-after photographs - which (starting with the second one below) will fade between "on" and "off" when clicked.
Link: http://www.boston.com/bigpicture/2009/03/earth_hour_2009.html