Last year U.S. President Barack Obama tossed a green gauntlet, challenging Americans to take action to better the environment in honor of Earth Day. Have you done your part to better the environment? Here's a recap of what tasks President Obama challenged us to. "I want you to take action -- in your home or your community; at your school or your business -- to improve our environment," Obama said in a videotaped message.. "It can be as simple as riding the bus or the subway to work, making your home more energy efficient, or organizing your neighbors to clean up a nearby park." To help Americans come up with ideas about helping the environment, an "Earth Day" page of resources was posted on WhiteHouse.gov in conjunction with Obama's challenge. "In the end, it's people like you -- the small business owners and community leaders; the teachers and the students; the young people and the grandparents -- who have made Earth Day so successful," he said. "And it's going to be up to you to make an even bigger difference over the next 40 years. So let's get to work."