Super Thermite, might it have been used?

It was thermate, a specific patented brand of thermite.
Steven Jones has found the chemical signature of thermate in samples of the 9/11 wreckage proving that it was used.
The EPA also did air quality samples at ground zero and found high traces of 1.3 Diphenylpropane (1.3 DPP) which is found in 'sol-gels' used in conjunction with thermite or thermate.

Dr. Steven Jones's work can be found here, along with alot of other scholars.
The Journal of 9/11 Studies
Scholars for 9/11 Truth

There is a lecture here by Professor Steven Jones Ph.D you should watch, it explains alot.
American Scholars Symposium 9/11 and the NeoCon Agenda - Los Angeles, California June 2006
There are newer lectures he has done that give updated and new information that is not included here, I would highly recommend looking for those also.

Happy hunting, and if you need help getting your hands on the updated lectures let me know I think I have them bookmarked somewhere.

Interesting new article on this

911research.wtc7.net...

Excerpt form entire article

Aluminothermics at the WTC The discovery of unexploded super-thermite in the WTC dust augments a large body of evidence pointing to the use of aluminothermic materials in the destruction of the skyscrapers. The present review looks only at the evidence of explosives found in the dust and debris expelled from the Twin Towers.