Furthermore, not that anyone is saying the contrary in this thread (very civilised discussion going on):
There are NOT two binary activities of stretching/exercise.
Weightlifting will provide an excellent stretch, done through a full ROM. A strict lunge: excellent for the hips.
Also, due to the principle or 'reciprocal inhibition', I have found that doing rear delt flyes with very good form for multiple sets of 30 reps per day is the best possible cure for a tight chest. By contracting the rear delts, the chest must relax.