To say that one specific interrogation technique is repsonsible for the prevention of very specific planned terrorist attacks sounds a bit...far fetched.
There are a whole slew of very affective techniques used by the CIA, and in Guantanamo - sleep depravation, stress positioning etc etc.
This is an interesting article:
http://www.americanthinker.com/2004/10/torture _as_an_interrogation_te.html
By the way, it's not written by some lefty liberal, but Major Anthony F. Milavic's, who had a 25 year Marine career included service as: an instructor in Communist Interrogation, Indoctrination, and Exploitation of Prisoners of War; a tactical interrogator in Vietnam and a CIA strategic interrogator; the principal intelligence officer of a Marine squadron, regiment, and division equivalent in combat; and, a DIA briefer for the CJCS/SECDEF.
So I think he knows what he's talking about.