I saw an interesting documentary yesterday called "we have ways of making you talk".
Was quite interesting to see both torturers and people that had been tortured sharing their point of view. Also showed how even ordinary civilians can be turned into torturers simply by being given orders to do so and told they are not responsible (here's a link about that
http://old.newhavenadvocate.com/articles/zap.html).
The conclusion was that torture be it mental or physical certainly is effective, but only undermines the governments applying them as they see it as more and more effective way their willingness to administrate torture becomes more carefree, and ends up being used on innocent people more often than guilty.
There is never a good reason to compromise our freedome or what we stand for, only then will the terrorists have won!