David Rovics, http://www.davidrovics.com/ is well known within the 9/11 truth community due to his song Reichstag Fire, http://www.archive.org/details/snowshoefilms
He recently wrote an article critical of the 9/11 truth movement and especially of controlled demolition theories, http://songwritersnotebook.blogspot.com/2008/03/91... and this was reposted all over the place including UK Indymedia, http://www.indymedia.org.uk/en/2008/04/395207.html and Common Dreams, http://www.commondreams.org/archive/2008/04/07/812... where it attracted a lot of comments...
Then last Tuesday he was on Kevin Barretts show, http://mp3.wtprn.com/Barrett/0804/20080408_Tue_Bar... and there is a new interview with him on UK Indymedia which also asks some questions on 9/11, http://www.indymedia.org.uk/en/2008/04/396101.html