How does Robin Williams best remember his friend Dana Reeve? For the way, he says, "she would light up a room." Christopher Reeve's widow, who died of lung cancer last month at 44, had the same effect on the 900 guests who attended a memorial service in her honor at Manhattan's New Amsterdam Theater April 10. "It wasn't morose," says friend Peter Kiernan, "it was a celebration." Among those attending were Lance Armstrong, Glenn Close and Norah Jones, who drew tears with her version of "The Nearness of You." As mourners filed out, most wore silver pendants bearing the Superman logo and the words "Go Forward." Fitting, said CNN's Paula Zahn, for a woman who faced her life's considerable challenges with "every piece of grit she had."