We can all go green this weekend and it will only take an hour of your time.  There's a worldwide event planned this weekend called Earth Hour.
    
Saturday night at 8:00 p.m., you can join millions of people who will be conserving energy just by turning off your lights for one hour.
    
It's an event the World Wildlife Fund dreamed up in 2007 and last year it was just for the city of Sydney, Australia.
This year, it's making it a global event.  More than 100 U.S. cities have said they will participate.
    
While the impact on the environment will be hard to measure, since it's difficult to know how many people are turning off their lights, organizers say anytime you reduce energy demand, you save fossil fuels used to generate electricity.
    
Again, Earth Hour is set for Saturday night at 8:00 p.m.  Of course, it will be most effective if you also turn off small appliances like your television.