While uneven wear on your tires definately appears to be the cause of your pulling issue, you should also try to address the root cause of it. Tires do not wear unevenly from side to side (which is causing your pulling problem) when the suspension is in good order. You should ask a good suspension shop to check all bushings in your suspension for dry rot or excess wear. They should check your tie-rods and lower ball joints for excess play, and they should check to see if your struts are bent or springs are sagging. If all of these items are in good order and your have a proper alignment, accidentally switching tires from side to side will typically cause more road noise but not pulling to the side.
I suggest for those that take their cars in for tire rotations to take a dry erase marker and mark each wheel "LF", "LR", "RF", "RR", respectively. Upon receipt of the vehicle, they should have moved the rears to the front on the same side, so the Left Front wheel should have the marking "LR", etc. This not only ensures you that the wheels are properly rotated, it also help the techs identify which wheel is which once they go to put them back on the car, and many are appreciative of the help.
Good luck!