Kimo--
The "auto pilot" feature of the game makes aileron trim not needed for the most part....toss in a quick "combat trim" toggle to on and then off again....and when you aircraft is intact its not really needed (unless you are a purist and don't ever use auto pilot or combat trim:) )
But as pointed out, when you have damage that results in a rolling moment (missing wing, split flap, etc...), it makes it a whole lot easier to fly home when you can trim some of the control forces out.