Re: Back of Hip Pain
Could be your sacro-iliac - mines the same. There's a heap of stretches you can do. Including pyriformis stretches.
Some good resources are painclinic.org and kalindra.com/sacroiliac.htm.
Its also important to have a strong core so any stability stuff you can do is good- strengthen the gluteus medius (look up the crab exercise) as well.
When mines really bad I go to the physio and he manipulates it and loosens it up.