I think the focus on who was or was not responsible should be secondary to the science and engineering debate. If people feel assured and comfortable with the official version of who was responsible, they could still explore the scientific debate from that standpoint.
This is the Architects & Engineers site:
http://www.ae911truth.org/en/home.html
Judy Wood's work is also interesting:
http://wheredidthetowersgo.com/
Cant access her official sites for some reason.
Yeah but what do you think? :D
As per my last PM, I don't have any particular knowledge of the processes involved in the collapse of the buildings at the WTC.
We do have regulations over here concerning 'Disproportionate Collapse' which relate to the ability of a building to stay standing following the damage or removal of key structural beams/columns. This came about following the collapse of Ronan Point in London in the 60's (due to a gas explosion I think, can't quite remember

).
I've seen a few different videos regarding the WTC collapses, those towing the official line refer to 'Progressive Collapse' which involves the damage to a structural element which in turn causes excessive loads to other structural elements, making them then fail, the process repeating until the building can no longer stand.
There are then a whole bunch of other videos which offer up the various conspiracy theories, I recall seeing one which claimed that there was the remains of a US warhead visible in the debris at the Pentagon. Another suggested the plane which crashed before allegedly reaching its target was actually shot down.
One of the more recent videos that I've seen concentrated on the WTC7 building and suggested it had been destroyed by controlled demolition.
I haven't really spent too much time looking at the conspiracy theories, but to me personally, it all sounds a bit far fetched.
I find the whole disaster quite interesting (as many people do), it's one of those events that I can instantly remember where I was, watching it on the news at a golf club, thinking a plane had accidentally collided with the towers, when the second plane then struck live on the news report.
I think it's an event which sparks the imagination and lends itself to conspiracy theorists very easily.