Weight training without a doubt is beneficial but that alone is not the answer. BTW treating Trigger Points is not treating the symptom. Many times the pain is located some distance from the actual trigger point that's why I mentioned referred pain.
I used to lift weights four days a week but these days I focus as much on flexibility as strength. I do yoga once a week and use Steve Maxwell's Encyclopedia of Joint Mobility which is a set of DVDs that focus on body weight exercises that work on strength and flexibility simultaneously. I also try to work in a couple of light kettlebell workouts but mainly I ride my bike.