I've got to say I don't much believe in the conspiracy of 9/11. Except for building 7.
WTC7.net the hidden story of Building 7: Videos Show Building 7's Vertical Collapse
The video's are pretty good evidence that something odd happened in #7. The twin towers went down because of the planes jet fuel. The pentagon hit was obviously a plane. One of the engines and landing gear are plainly visible in lots of pics. But I have never heard of an acceptable explanation for WTC7.