Well, that was quick (caffinee is a wonderful creation).
I dont know where my head was, but it seems things were rattling around too much in my head, so I say we start from the beginning. First, turbojets:
A turbojet gains thrust from the interaction of hot, compressed exhaust air with cool ambient air. This air is comressed by the compressor section of the engine, then superheated in the combustion section wherwe it tries to expand away. It cant go back the way it came under normal situations (and when it does, you get a 'compressor stall' with a loud bang and flames shooting out both ends), so the expanding exhaust air follows the path of least resistance and goes out the back of the engine, into the turbine section.
The stators in the turbine section deflect the expanding gasses to impact at a more usable angle on the turbine blades, which forces them to move and turn the wheel they're attached to. The turbine blades themselves are also curved, partly to gain a little more energy from deflection forces, and partly to help direct the air into the next stage of stators. Wash, rinse, repeat, until you run out of turbine stages. Now, as Sir Newton teaches us, with every action, in this case the air being deflected by the stators, there is a reaction, the turbine case (and the engine it is attached to) trying to rotate in the direction opposite the direction the air is deflected in. There's your torque.
Now, for some reason I said that the comressor creates torque forces as it's compressiing, agreeing with someone else here. This is FALSE. The compressor creates a torque load, which is overcome by the compressor shaft, which is spun by the turbine wheels. The more load, the more force is required to over come it, simple mechanics there. And with more force being created to spin the turbine, more force is acting on the stators, and thus more torque is created. All this time, the force is coming from that hot air from the combustion section expanding and trying to get out of the damned engine!
Now, if you use up all of your energy just keeping the compressor turning, then the air will of completely expanded as it exits the turbine, and you get no jet thrust and little airflow. This is what happens with turboshaft designs, as they draw out the maximum ammount of power from the expanding gases with the power turbine (or the hot-section's turbine, in the case of a direct-drive turboshaft).
Ok, next lesson, bypassing fans. Hitech is correct in his statement of sources of torque from a bypassing fan. The torque forces are created from the hot section overcoming the load of the high and low speed compressors, by blasting more hot air through the turbine, which creates more force on the turbine blades to spin things, and creates more force on the stators to direct the air to spin things.
Still here? Ok...
Next, turbo props. A direct-drive, non-reduced turboprop with no gear-box between the engine and the prop would generate torque in the same way as a bypassing fan or turbojet. It would also self-destruct the prop from the gee forces, so we stick a reduction gear on it. This now adds a new load, as well as another kink in the torque problem. We now have something mechanical, bolted to the air frame, that is trying to spin a propeller. And with the load the propeller is creating, we have a reaction trying to spin the gear-box it's attached to. That's torque, folks.
Dont beleive me? Then tell me what would happen if you hung a 182 with the Power Pak STC performed (thats a little turboprop, Allison A250 model) by it's prop and fired it up? If you try to tell me the aircraft wouldn't end up spinning around, then you need to take what you're smoking and share it with the rest of the class.
PS: And if anyone here questions anyone's certifications, I know how to get to the FAA's Airmen Inquiry site. I'll happily give anyone that requests it my real name to look up my A-P ticket
