Last night Nick Lachey, Ashley Tisdale and Al Roker hosted the tree lighting ceremony at Rockefeller Center in NYC. The beautifully lit backdrop included performances from Celine Dion, Natasha Bedingfield, Tony Bennett and Josh Groban. NBC star Brooke Shields came out to promote Lipstick Jungle while Jason Lee plugged his family film Alvin and the Chipmunks. The coolest thing about the evening was finding out that this year's tree has "gone green" by using energy-efficient LED lights. What a great new tradition to incorporate this holiday season. Click here to learn how to do this in your home this year.