Festive lights, Michael Phelps, Alan Greenspan (8 images)

A tree decorated with festive lights glows at dusk, near Arosa, Switzerland. (AP Photo/Keystone, Alessandro Della Bella)

U.S. swimmer Michael Phelps is seen at the Manchester Aquatics Center in Manchester, England. Phelps and the American swimming team are taking on a European team in the 'duel in the pool' on Friday and Saturday. (AP Photo/Simon Dawson)

Former Federal Reserve Chairman Alan Greenspan arrives at a Senate Homeland Security and Governmental Affairs Committee hearing on Capitol Hill in Washington, DC. The committee is hearing testimony on why Congress should establish a bipartisan task force to help safeguard Americaís economic future and proposals to secure It. (Photo by Mark Wilson/Getty Images)

AEK Athens' Youssouf Hersi, from Netherlands, pulls off his shirt to throw to the supporters at the end of their Europa League group I soccer match against Benfica, at Benfica's Luz stadium in Lisbon. Benfica defeated AEK 2-1. (AP Photo/Armando Franca)

An Afghan man looks on as a United States Marine from the 2nd Battalion 2nd Marines and an Afghan soldier search his house during an operation in the Garmsir district of the volatile Helmand province, southern Afghanistan. (AP Photo/Kevin Frayer)

Members of the Danish Ogaden community demonstrate outside Bella Center, the venue of the U.N. Climate Conference in Copenhagen, drawing attention to the environmental situation and the suffering of their people in Ogaden, Ethiopia. The largest and most important climate change conference is underway in Copenhagen, aiming to secure an agreement on how to protect the world from calamitous global warming. (AP Photo/Peter Dejong)

Tuberculosis and HIV patient Sunthaiya Suthsai sits on his bed at Wat Prabat Nampu in Lopburi, Thailand. Simple TB is simple to treat, a $10 course of medication, but the pills must be taken in specific combinations for six months to completely wipe out the bacteria. If treatment is stopped short, the TB learns to fight back against the drugs, mutating into a tougher strain for which few, if any, medications exist. It can cost $100,000 a year or more to cure drug-resistant TB, which is described as multi-drug-resistant (MDR), extremely drug-resistant (XDR) and completely drug-resistant (CDR). (AP Photo/David Longstreath)