In the county clerk's office at San Francisco's City Hall, Ed Rittenhouse was waiting to serve as a witness to the gay marriage of two friends on Feb. 26 when Rosie O'Donnell strode in, accompanied by her partner of six years, Kelli Carpenter O'Donnell (who legally changed her name last year). "Kelli was sweet. She shook my hand," says Rittenhouse. Rosie didn't. "She looked stressed. She just wanted to get [a marriage license] and get on with her plans."

And so she did. Shortly after 1 p.m., city treasurer Susan Leal pronounced Rosie, 41, and Kelli, 36, "spouse and spouse," using words the couple chose. "I had tears when I saw tears well up in their eyes," Leal recalls. "Even though Rosie is a comedian, there were no jokes; she was serious." In fact she was making a political statement: That morning she told Good Morning America that her wedding was a protest against President Bush's "hateful" proposal to seek a constitutional amendment banning gay marriages, including the more than 3,300 performed in San Francisco since Mayor Gavin Newsom gave the green light Feb. 12.

After their nuptials Rosie introduced Kelli to reporters on the steps of City Hall as "my brand-new wife." Then the newlyweds hopped a flight back to New York—and reality. "With four kids under 8," deadpanned Rosie, "there will be no honeymoon."

Get up-to-the-minute celebrity news and photos on your cellphone, iPhone or Blackberry at www.people.com!