Could we at least make an exception for Helen Thomas?
Seriously, there are circumstances in which I feel torture is justified. It is certainly justified to get info that a nuclear device is planted in NY and the clock is ticking.
Besides my moral objection to such a technique, I doubt it would be very useful in such a situation. Torture can serve two purposes, basically: to punish/humiliate (the most popular historical use) and to extract information.
The former can be done by anyone and does not require a particularly skilled operator. If you are torturing simply for the sake of inflicting pain, it process can be as long or as short as you would like it, depending on how much pain the torturer can stand to inflict (as, unless the torturer is a sadist, often difficult to do).
The latter of the two methods is entirely different, though. Torture as a means to extract information is often an extremely lengthy process. Most people can withstand a great deal of physical pain, so torture used to extract information must be a combination of physical AND mental torture techniques--the only way to extract reliable information. Days or weeks certainly wouldn't be out of the question as far as a reasonable time limit here.
An interesting book on the subject, although to my knowledge, out of print, is "Physical Interrogation Techniques," by Richard Krousher.
Of course there are things we will do to get information from prisoners with information. Ultimately though, the information is won when their mind is overthrown... and outright causing of pain, or fear of pain, is only the least civilized way to achieve that. I would rather not put interrogators, and the varsity mind games they play, in the same category as sadistic abuse of an enemy out of hatred.