I don't have any pain associated with the clicking, which is why I'm so reluctant to go to the doctor about it. A cursory search online suggests clicking without pain is nothing to worry about, which doesn't exactly encourage me to seek out his help. Someone suggested that perhaps my outer thigh muscles are getting too much stronger than my inner thigh muscles and it's pulling slightly at my kneecaps when I walk as a result. I have no idea if the logic behind that is sound, but it is true that my outer thighs are far stronger than my inner. I do both the abductor and adductor machines at the gym, maintaining the same weight on each, and the abductor isn't a challenge at all at my current weight. On the other hand, the adductor is still a struggle for me to do 3 sets of 12.
Arg. I'm just frustrated. I'm going to try adding the knee machine at the gym and laying off the abductor machine completely to focus on strengthening that inner muscle. I might start looking for some inner thigh exercises I can do with the knee exercises I do at night, too. It certainly can't hurt.