It is one of my most useful tools. I take my Bushnell Scout with me whenever I am out hunting (bow, muzzleloader, handgun, rifle and shotgun) and especially scouting. I feel that the most productive thing you can do with it is just practice ranging while out scouting. Kind of like stump shooting with a bow, you get to practice estimating distances.
Now when actually hunting you usually don't have time to range an animal unless it is really far away and you are setting up a stalk. However if you range things around you it will give you some better idea of what range on the animal is when you go to make your shot. Even when bird hunting in the desert you can occasionally range some brush ahead of you and it will keep you fixed as you move on. Distances can be decieving!
Another really useful thing to do with your rangefinder is to accuratly record the distance of the shot that you made. Kind of like a little "Deliar" fish scale. Often you can't walk a straight line from where you shot to where the animal was.