First there was the Onion's brilliant point/counterpoint on the question, where an AQ press rep got salty with a US Truther for trying to deny Sunni jihadists the credit they deserve:

And now there's reality:

Osama bin Laden's chief deputy on Tuesday denied a theory that Israel carried out the Sept. 11 attacks and blamed Iran and Shiite Hezbollah for spreading the idea to discredit the Sunni al-Qaida's strike against the U.S. The comments in a recording posted on an Islamic Web site reflected the increasing criticism by al-Qaida's No. 2 leader Ayman al-Zawahri against Iran... One of the questioners asked about the theory that has circulated in the Middle East and elsewhere that Israel was behind the 2001 attacks on the World Trade Center and the Pentagon. Al-Zawahri accused Hezbollah's Al-Manar television of starting the rumor. "The purpose of this lie is clear - (to suggest) that there are no heroes among the Sunnis who can hurt America as no else did in history. Iranian media snapped up this lie and repeated it," he said.

Really? Really?

References:
* Al-Qaida No. 2 says 9/11 theory propagated by Iran [AP]

Previously:
* Iran, Hamas, And Islamic Jihad Meet In Syria To Plan Mideast Turmoil
* Clowns. Total Clowns (UN Speakers Edition)
* Hamas Media Lovefest Goes Awry As Green-Headband Wearing Farm Animals Begin Defecating, Having Sex