The rumor that Michelle Obama railed against "whitey" in a diatribe at Chicago's Trinity United Church of Christ has circulated on conservative Republican blogs for weeks and was repeated by radio talk show host Rush Limbaugh.

The rumor included claims of a videotape of the speech that would be used to bring down Obama's candidacy this fall.

"No such tape exists," the Obama campaign responds on a new Web site, www.fightthesmears.com. "Michelle Obama has not spoken from the pulpit at Trinity and has not used that word."

The site was launched to debunk false Internet rumors that play on racial and religious fears.

Here's a sample:

"On May 30, Rush Limbaugh said he had heard a rumor that a tape exists of Michelle Obama using the word 'whitey' from the pulpit of Trinity United Church of Christ. Truth: No such tape exists. Michelle Obama has not spoken from the pulpit at Trinity and has not used that word."

It goes on to say that a blogger named Larry Johnson "wrote on May 31 that he would add 'New and dramatic developments. This is a heads up. I’ll post the news Monday morning by 0900 hours. Now I know why people who have seen the videotape say it is stunning. Barack’s headaches are only starting.'" But Johnson posted no such update.

"Sleazemeister Roger Stone said on Fox News on June 1 that 'there's a buzz, which I believe now to be credible, that some indelible record exists' of a tape of Michelle Obama using the term 'whitey.'" But the site says that Stone conceded on June 2 that he hasn’t met anyone who has seen the tape and that it therefore may be a hoax.

The site repeats the innuendos, in some cases explaining and linking to where they came from, debunks them and encourages people to give the campaign their e-mail addresses to "spread the truth."

Other false rumors rebutted on the site are that Obama is a Muslim (he's a Christian), that his books contain racially incendiary remarks (fabricated and out-of-context quotes are cited), and that he won't say the Pledge of Allegiance (a video shows him leading the pledge in the Senate -- with his hand over his heart).