WASHINGTON - (AP) - President Barack Obama said Friday he washonored and humbled to win the Nobel Peace Prize and would acceptit as a "call to action" to work with other nations to solve theproblems of the 21st century. A beaming Obama told reporters in the White House Rose Gardenthat he wasn't sure he had done enough to earn the award, ordeserved to be in the company of the others who had won it beforehim. But, he said, "I will accept this award as a call to action, acall for all nations to confront the challenges of the 21stcentury." Obama will travel to Oslo, Norway, in December to accept theaward. Obama, 48, is the third U.S. president to win the prize while inoffice, after Theodore Roosevelt and Woodrow Wilson.