"It traffics in ugly, unfounded accusations of extraordinary evil against fellow Americans."
So writes Senator John McCain in the foreword to "Debunking 9/11 Myths: Why Conspiracy Theories Can't Stand Up to the Facts." This is the well-known analysis published in Popular Mechanics in March 2005, plus an afterword dated June 2006. It is good to have this clearly presented and updated material in book form. It will be available on August 15th, but you can order it at the first link now. (I received an advance copy.)
UPDATE: The whole text of the book is updated and expanded, not just the afterword.