U.S. Treasury Secretary Timothy Geithner (L) and Federal Reserve Chairman Ben Bernanke attend a ceremony to debut the new design for the US$100 note at the Department of the Treasury in Washington, April 21, 2010. A newly designed $100 note contains advanced security features to combat counterfeiters, but older $100 notes will remain in circulation after the new currency is released in February 2011, top U.S. Treasury and Federal Reserve officials said on Wednesday. [Xinhua/Reuters]