I watched videos over and over again of the tower's collapse. It conicides with NIST findings.
I still don't like building 7. It was "pulled" The owner of the building ordered, "pull it" and it went down. Had it fallen on it's own I can see your crater theory, but there had to be explosives in the building in order to be "pulled", and they surely didn't set those amidst the chaos of that day.
Silverstein stating he ordered the "pull"
http://www.youtube.com/watch?v=j2q2mD2HaKA&NR=1
edit:I like PBO's take. The aliens did it! Ahhhhh