WASHINGTON, USA: The blogs are alive with the sound of Sarah.

Republican candidate John McCain's staffers may deplore the online rumor mill that forced them to announce the pregnancy of newly minted running mate Sarah Palin's 17-year-old daughter.

But experts have some perhaps unwelcome advice: Get used to it.

"It used to be that a rumor would float across your desk and you'd say, 'That's just so outrageous we're not even going to respond to it,'" said Republican strategist Todd Harris, a former McCain spokesman. "But nowadays you really have to push back forcefully against almost every single bit of gossip and rumor."

Palin's announcement disrupted the campaign's carefully orchestrated plan to introduce the little-known governor to the public in a high-profile speech on Wednesday. Instead, it prompted reporters and bloggers to dig further into Palin's background and question the wisdom of McCain's pick.

"It probably let the cat out of the bag before they intended to let that information out," said Republican communications consultant David All.

Palin announced her daughter's pregnancy to knock down speculation that her five-month-old son is actually the teenager's child.

McCain's rival in the November 4 election race, Democrat Barack Obama, has also battled the online rumor mill. Obama's campaign has set up a Web site to knock down false reports, spread via e-mail, that he is Muslim or harbors anti-American sentiments.

Blogs played a significant role in the 2004 election, but the 2008 race has seen even newer types of communications play a significant role. Obama has reached young voters through text messaging and social-networking sites like Facebook, while incendiary speeches by his former preacher Rev. Jeremiah Wright were viewed widely on the YouTube video site.

As Republicans absorbed the news about Palin's daughter inside the convention hall, rock-throwing protesters outside coordinated their movements via the Twitter "micro-blogging" service.

Across the river in Minneapolis, the libertarian-leaning former Republican candidate Ron Paul prepared to rally 10,000 of his tech-savvy followers, who have used specialty news services like Digg to promote his views.

The new media amplify, and strengthen, what might previously have been simple comments shared by neighbors over the back fence, and make them too dangerous to ignore, said Andrew Rasiej, a Democratic strategist and founder of Personal Democracy Forum, a grass-roots politics website.

"The McCain campaign I believe had no choice but to respond to the buzz that was churning on the Internet," Rasiej said. "To ignore it any further would have ceded the hill to the revolutionaries who were demanding answers online long before the mainstream media even opens its mouth to ask the question."