I find that exercise in general helps a lot, especially heavy weights. My back pain disappeared once I hit a heavy, mass-building routine. Work your legs. Work your core. Strengthen your back. Work on your posture. Use stretches and yoga postures.
Another thing to consider, which has made a world of difference to me, is your mattress. Get a good memory-foam mattress and your back pain will fade away.
Yoga & stretching, swimming & pilates are some to name a few. No matter what you do just make certain that your body is up to the task and don't ignore any signs it may give to you that you may need a rest or need to try a less intense exercise. When it comes to pain your body knows best!