Bill Gates and Warren Buffett are the two richest men in America and are well known for their philanthropic efforts. Now, the two have joined forces to ask other wealthy Americans to take “the Giving Pledge,” which means they’ll agree to give AT LEAST half of their wealth away to charitable causes. So far Gates and Buffett have found 40 takers, including T. Boone Pickens, Barron Hilton, Ted Turner and New York mayor Michael Bloomberg. For more information, click here.