CORRECTION 6/26/07:

Correction to: "Skeptics" or Dupes? Skeptic Magazine Not So Skeptical of 9/11 Lies

The Skeptic Magazine article was from the November/December 2006 issue, and publication preceded the date of publication of Debunking 9/11 Debunking.

The Popular Mechanics nonsense was under attack for a long time, however, before the release of the Griffin Debunking 9/11 Debunking book. Immediately upon publication of their first article, rebuttals appeared, most notably Jim Hoffman's:

Popular Mechanics Attacks its '9/11 Lies' Straw Man
http://911research.wtc7.net/essays/pm/index.html

Updated versions appeared in 2005 (more than a year and a half before the Skeptic article):

Popular Mechanics' Deceptive Smear Against 9/11 Truth
http://www.911review.com/pm/markup/index.html

David Ray Griffin directly addressed Popular Mechanics several times:

9/11 and the American Empire by David Ray Griffin
http://www.globalresearch.ca/articles/GRI505A.html

The Destruction of the World Trade Center:
Why the Official Account Cannot Be True
http://www.911review.com/articles/griffin/nyc1.html

Of special interest here is a link between Hearst Corporation CEO Victor F. Ganzi and the one and only C.I.A.:
http://www.911review.com/disinfo/press/index.html#pm

More 2005 work in response to the Popular Mechanics lies:

Alex Jones Responds To Ben Chertoff, Popular Mechanics 9/11 Debunking Campaign
http://prisonplanet.tv/audio/090305alexresponds.htm

Griffin's August 2006 CBC News interview should have been a tip off to Skeptic Rag as well:

"Well, [Popular Mechanics' Book] is one of the most disgraceful publications that has ever appeared, and as I’ve said in my new book, the Popular Mechanics owes the American public for putting this out – it is simply a disgrace."
http://www.cbc.ca/sunday/911griffin.html