It took me half an hour to walk up Avenida de Mayo today. On my way, I passed tens of thousands of people swarming towards the plaza to commemorate thirty years since the military coup that ousted the governent and ushered in a violent dictatorship. Over the seven years that followed March 24, 1976, 30,000 people were ´disappeared´by the military regime - around the same number of people that are on the streets tonight, shouting, dancing, banging drums and hurling slogans into the air. Thirty years ago, they would have been afraid to raise their voices. But three decades on, the fear is gone and has been replaced by anger, and a sense of triumph at having come through such a dark period unbeaten. There's even a kind of carnival atmosphere in the crowd today, with some people dressed up in colourful costumes and dancing samba-like through the street. And today´s protest is a typical Argentinian protest. It smells of barbecued meat (makeshift barbecues are dotted around the square to feed the hungry demonstrators) and sugar coated almonds. And the slogans keep repeating. No to the ALCA (the Free Trade Agreement of the Americas), no to the repayment of Argentina´s external debt, no to Argentinian troops in Haiti. Every ten minutes, someone yells through the loudspeaker: "The thirty thousand disappeared." And the crowd yells back: "Present, present, present for ever." Then it changes to a chant in support of the Mothers of Plaza de Mayo, a group of remarkable women who defied the junta, demanding to know what happened to their lost children. "The Mothers of the Plaza, the people embrace you." At one stage, as I moved out of the square, I got caught in a crowd of dozens of young people jumping as they sang: "You have to jump. You have to jump. Whoever isn´t jumping is a member of the military." I passed hundreds of people carrying pictures of the disappeared on huge placards over their heads. I passed human rights groups. I passed unions. I passed neighbourhood groups. I passed militants. And as I walked, every now and then running into a familiar face in this crowd of thousands of thousands, I felt a buzz that was strangely joyous, despite what the date signified. It felt like things can change.