Here is a great article on how physical therapy can be a benifit to treating your chronic pain.
Chronic Pain Treatment: Working Through the Pain
Along with this article, here are two additional tips to finding a good physical therapist:
1) Look for a physical therapist that treats patients for more than 30 minutes at a time. Thirty minutes or less is not enough time to really get in there and work on those trigger points.
2) Look for a physical therapist that is knowledgeble in manual therapy techniques (i.e. strain-counterstrain, soft tissue massage, muscle energy techniques, and trigger point release to name a few). While theraputic exercise is important as well, manual techniques are critical to chronic pain management.
Hope this helps,
Writer of the physical therapy section titled "Ken's Corner" in the Fibromyalgia Network Journal