mjhamilton wrote:I guess as the ARB can also sometimes be referred to as a 'torsion' bar this would make some sense
Torsion: Torsion refers to the twisting of a structural member loaded by torque, or twisting couples.
The humps in the middle are the torsion/twist load points...
I bet (and am interested if someone would check) when put on the car and loaded up the bar is symetrical.. so this loads it with torsion stress so when one side of the suspenstion moves this is amplified to the other side to improve reactive response... 
God.. I really am talking bollox now but it makes sense in my old engineering head.. 
yeeeaahhhh

thats the 1 lol
i cant "engineer" a roll bar but basically you have hit the nail on the head about how they work, they tie both sides of the suspension together and reduce body roll
heres a cut and paste for you to engineer lol
A stabilizer bar tries to keep the car's body flat by moving force from one side of the body to another. To picture how a stabilizer bar works, imagine a metal rod that is an inch or two (2 to 5 cm) in diameter. If your front tires are 5 feet (1.6 meters) apart, make the rod about 4 feet long. Attach the rod to the frame of the car in front of the front tires, but attach it with bushings in such a way that it can rotate. Now attach arms from the rod to the front suspension member on both sides.
When you go into a turn now, the front suspension member of the outside of the turn gets pushed upward. The arm of the sway bar gets pushed upward, and this applies torsion to the rod. The torsion them moves the arm at the other end of the rod, and this causes the suspension on the other side of the car to compress as well. The car's body tends to stay flat in the turn.
If you don't have a stabilizer bar, you tend to have a lot of trouble with body roll in a turn. If you have too much stabilizer bar, you tend to lose independence between the suspension members on both sides of the car. When one wheel hits a bump, the stabilizer bar transmits the bump to the other side of the car as well, which is not what you want. The ideal is to find a setting that reduces body roll but does not hurt the independence of the tires.