The United States and several other delegations walked out of the United Nations General Assembly tonight during a speech by Mahmoud Ahmadinejad — after the Iranian president made repeated anti-Semitic remarks and hurled attacks at the U.S. Earlier today, it was Libya's Moammar Gadhafi — a longtime sponsor of terrorist atrocities — at the center of his own circus. He gave a rambling diatribein which he accused an unnamed military of creating the H1N1 swine flu and tore up a copy of the UN Charter. So tonight we ask you: Has the UN become irrelevant — an international joke? Tell us what you think. You can follow "Nightline" anytime on Twitter: http://twitter.com/Nightline.