Have the same problem. Between the 2-hours each way commute, sitting at work all day, and sit-down winter hobbies, my back has been screaming for attention.
Started a beginner yoga class this fall and it has done wonders for me. I do some of the simpler (and less noticeable) relaxation exercises on my breaks at work, on the train, etc., and a half hour before bed...no more backaches!