'They were about to walk off with the most prestigious undergraduate degree in America, reports David Abel of the BostonGlobe.com. 'But many of the nation's future leaders were suddenly reduced to gushing: ''I was just, like, `Wow!' I mean, was he not so cool?'' Here was the scene yesterday in Harvard Yard moments after the short, stubble-chinned object of their awe concluded his commencement address to the class of 2001: Students swooning. Others moved to tears. Many more swarmed around the man, angling for autographs, a kiss, or a handshake, and - of course - hoping beyond all hope that he might offer a ticket to one of his three remaining sold-out concerts in town this week. They even screeched his name: "Bono! Bono! Bono!" The Irish rock star spoke at length about the problems of poverty and debt in the Third World, but the rhetoric was lost on those who simply wanted a glimpse of U2's ubiquitous front man. "Bono is my all-time idol," said Jennie Timoney, 20, a junior from Dublin, who managed to shake his hand and extract a promise for tickets to a future concert in Ireland. "He is the coolest guy in the world, and I just met him! Oh my goodness!" The exclamations echoed through the exultant crowd. Julieta Gonzalez was weeping, almost hyperventilating. "He just kissed me!" said the 22-year-old who came to Cambridge from Mexico to see her friend graduate. "Bono just kissed me!" Wearing combat boots, blue sunglasses, and a camouflage green cap turned backward, Bono was greeted with a burst of applause and hoots of adulation when he stepped on the podium yesterday afternoon and introduced himself: "My name is Bono and I am a rock star." This was his explanation for why he sings rock music: "Rock music to me is rebel music," he told the crowd. "I'm rebelling against my own indifference. I'm rebelling against the idea that the world is the way the world is and there's not a damn thing you can do about it. So, I try to do a damn thing." In explaining his recent campaign to pressure wealthy countries to forgive the debts of poor countries, he startled a few in the audience when he praised Harvard's incoming president Lawrence Summers by saying: "He is a nutcase and a freak ... Mr. Summers is culturally challenged ... When I told him I was from U2, he had a flashback from Cuba." Later, he explained the former US Treasury secretary played a significant role in helping persuade Congress to pass a debt-relief package. "When I asked him to look up from the numbers to see what we were talking about, he did more than that, he did the hardest thing of all, he saw through the numbers," Bono said. "He was passionate." The singer also spoke to students about another of his long-held views: "The culture of idealism is under siege, beset by materialism, narcissism, and all the other isms of indifference," he said. "Worse still, idealism has been reduced to a marketing tool."