9/11 Theories

I have just started reading one of the many books claiming that the events of 9/11 were in some way a US government conspiracy. The author sets his stall out in the first chapter by broadly outlining his lines of research. That was where I was when I put the light out but I remember thinking it was strange (to me) that bin Laden had apparently done nothing to muddy the waters. Then, this morning, I read New Osama bin Laden tape claim - World - Times Online
Almost a conspiracy theory in itself!
I found it impossible to keep up with the flood (or is avalanche better?) of publications immediately after 9/11. I read the Commission Report. This was drawn-up almost as a novel and seemed clear and authorative. As time passes, people find cracks in the casing and I would think that there is now as much against the 'official' verdict as there was in support.
Some of the internet summaries and reports I have heard regarding the theorists works lack only James Bond, tricked-out cars and beautiful nymphomaniacs.