Flowers are left at the memorial for U.S. President John F. Kennedy in Hyannis, MassachusettsPresident Barack Obama will sign up for former President Invoice Clinton and former Secretary of State Hillary Clinton on Wednesday in a wreath-laying ceremony at John F. Kennedy's grave to commemorate the fiftieth anniversary of his assassination. First woman Michelle Obama may even attend the ceremony at Arlington Nationwide Cemetery on November 20, two days sooner than the anniversary of the president's demise, a senior administration reliable said on Saturday. Also on Wednesday Obama will present the Presidential Medal of Freedom, established with the aid of Kennedy, to recipients at the White Home.