Regarding the Snopes link Kim C provided above, while I do, in fact, pretty much agree with their analysis, I think they're stepping a bit outside if their bailiwick in offering that analysis before the protest has even taken place.   

Claim:   Participating in a 'Not One Damn Dime Day' is an effective way to protest the war in Iraq.

Status:   Probably not.

What they are doing is speculating and offering their opinion, which, though it may be a very educated opinion, is still just an opinion.

Snopes's reputation has been built on trying to provide factual information to help prove or disprove the validity of certain things some people believe to be true. They are not proving or disproving anything regarding "Not One Damn Dime Day". Maybe, come next week they can say factually that the protest didn't work, but all they can possibly do at this point is to offer an opinion and, since many people look to them as an authoritative source for factual information, some people will automatically give Snopes's opinion the weight of fact. They need to just go back to debunking myths and rumors.