Attorney General Eric Holder testifies before the House Judiciary Committee. He faces tough questions about the Justice Department's "Fast and Furious" gun-control program. Jim Watson/AFP/Getty Images hide caption

U.S. envoy Todd Stern delivers a speech on Thursday in Durban, South Africa, during the U.N. Climate Change Conference. Stephane De Sakutin/AFP/Getty Images hide caption

Newt Gingrich, shown with his wife, Callista Gingrich, attends a pre-debate rally sponsored by the Faith and Freedom Coalition earlier this year in Florida. The thrice-married former House speaker, who cheated on his first two wives and was punished by the House for ethical violations, is now outperforming family man Mitt Romney among Iowa's evangelicals. Mark Wilson/Getty Images hide caption

Led Zeppelin reminds one listener of a mother's unconditional love. Dick Barnatt/Redferns hide caption

Foster Smith (left) and his best friend, Mark Ballard (right), met when they were 12 years old. After losing his job, and his ability to make rent, Smith moved into a room in Ballard's College Park, Ga., home. Courtesy of Foster Smith hide caption

Lawyer and anti-corruption activist Alexei Navalny, left, is taken to court in Moscow on Tuesday. Navalny was detained Monday along with 300 protesters who rallied against what they called vote rigging during Sunday's parliamentary election. Mikhail Metzel/AP hide caption

The Giant Theremin emits not only tones but also some prerecorded musical sounds. Courtesy of the artist hide caption

Christopher Miller samples sediments from an excavation site in South Africa. Archaeologists found layers upon layers of burned bedding material, indicating that the hunter-gatherers who lived here 77,000 years ago stayed for a long time. Courtesy of Lyn Wadley hide caption