By KATHARINE Q. SEELYE
Nancy Pelosi, the speaker of the House, was asked a question here at a bloggers conference about energy. Ms. Pelosi glanced at her BlackBerry, noting that she had an e-mail message from a friend on that very subject.
With that, the voice of former Vice President Al Gore came over the public address system, as if reading the e-mail message: ''Dear Nancy.'' This created a sea of quizzical looks in the audience, then gasps, cheers and a standing ovation as Mr. Gore strode on stage.
The surprise appearance produced the first electric moment at the conference, the Netroots Nation, an ever-widening group of progressive bloggers whose major interests -- the war in Iraq, the environment and technology -- mesh well with Mr. Gore's current pursuits. Indeed, many in the crowd of about 3,000, most of whom are supporting Senator Barack Obama, the likely Democratic presidential nominee, were overheard saying they wished Mr. Gore were running for president.
As waves of cheers washed over the cavernous convention center, Mr. Gore said to Ms. Pelosi, ''We ought to take that act on the road.''
''We are on the road,'' she replied.
''Well, I feel right at home here, I'll tell you,'' he said.
Mr. Gore, later answering questions from the audience, said he would not accept a role in the next administration. The best use of his talent and experience, he said, is ''to focus on trying to enlarge the political space'' within which politicians can address the climate crisis.
''I have seen firsthand how important it is to have a base of support out in the country for the truly bold changes that have to be made now,'' he said, noting that is why he intends to devote his life to bringing about ''a sea change in public opinion.''
He repeated the challenge he issued to the country on Thursday to produce 100 percent of its electricity from renewable energy and clean, carbon-free sources within 10 years. And he called on the bloggers to help achieve that goal, saying they were on the leading edge of reclaiming democracy for the grass roots.
As the morning began, Ms. Pelosi, Democrat of California, appeared on stage with Gina Cooper, the moderator and an organizer of the conference. The bloggers had submitted questions in advance and voted on them; the first was why Democratic leaders in the House were reluctant to take up impeachment proceedings against President Bush and Vice President Dick Cheney. Ms. Pelosi said the House was considering contempt resolutions against Karl Rove, the president's former top adviser.
Ms. Cooper asked Ms. Pelosi whether Mr. Rove, if found in contempt of Congress, would be put ''in that little jail cell that's in the basement of the House.'' The audience cheered. Ms. Pelosi replied that Representative John Conyers Jr., the Michigan Democrat who is chairman of the Judiciary Committee, had told her, ''Leave it up to me.''
She was next asked about the wiretapping bill, detested by many progressives. She said the House version was better than the Senate's and blamed Senate Democrats for approving a version that ''enabled the Republicans to send that bill to the House.''
Ms. Cooper, who periodically interceded with pointed comments that were much appreciated by the audience, told Ms. Pelosi, ''It sounds like your colleagues need to get with the program with the American people.''
Asked if she would redirect money from abstinence-only programs to sex education, Ms. Pelosi said, ''Yes,'' adding that the current program ''caters to a radical right-wing view.''
When Mr. Gore addressed the group, he noted first that the polar ice cap, which is about the size of the continental United States and has been in existence for three million years, had a 75 percent to 80 percent chance of melting in five years.
Mr. Gore also mentioned his energy challenge, which brought another standing ovation. He said he was trying to recruit ''an army'' of 10 million citizens to build political consensus across party lines for the energy challenge, and directed the audience to wecansolveit.org, the Web site of his group, the Alliance for Climate Protection.
''I need your help,'' Mr. Gore said, a plea that bloggers heard repeatedly throughout their conference, which began Thursday and ends Sunday, as speaker after speaker for various causes took note of their increasing influence within society.
Mr. Gore promised them that the alliance would not turn partisan or take up some other agenda and that he was in it ''for the long haul.''
Ms. Pelosi was asked whether Congress would accept Mr. Gore's energy challenge. ''It is absolutely possible to do so,'' she said.
She added that without Mr. Gore, ''there would be no Netroots Nation; we would simply not have the technology.''
As a reminder of the flap caused years ago -- when he got tagged with having said he ''invented'' the Internet, although he had not used that word and had, in fact, helped legislatively to create it -- he smiled at Ms. Pelosi's comments and said, ''I think I'll refrain from saying it.''