Democratic presidential nominee U.S. Sen. Barack Obama (D-IL) (R) and his vice presidential nominee U.S. Sen. Joe Biden (D-DE) wave to crowd after Biden addressed the 2008 Democratic National Convention in Denver, Colorado, August 27, 2008. U.S. Senator Barack Obama (D-Il) is expected to accept the Democratic presidential nomination at the convention on August 28. REUTERS/Chris Wattie (UNITED STATES)