July 13, 2008 (23 images)

Chinese construction workers stand on scaffolding erected to build an Olympic-themed exhibit on Tiananmen Square in central Beijing July 13, 2008. China vowed Sunday to step up security for the upcoming Olympics, warning of an unprecedented threat to the Games amid reports that two "terrorists" were executed in the mainly Muslim far northwest. (UPI Photo/Stephen Shaver)

Chinese street cleaners walk past a massive billboard of a USA basketball player, about to slam dunk over an opponent, adorning one of Nike's flagship stores just opened in downtown Beijing July 13, 2008. Beijing has been overwhelmed with Olympic fever, with most domestic and international sporting good stores now using Olympic themed advertisements to attract consumers. (UPI Photo/Stephen Shaver)

British actress Camilla Rutherford attends the premiere of "Wall-E" at Empire, Leicester Square in London on July 13, 2008. (UPI Photo/Rune Hellestad)

The Robot Wall-E attends the premiere of "Wall-E" at Empire, Leicester Square in London on July 13, 2008. (UPI Photo/Rune Hellestad)