I <3 yoga, so much so that I should probably start doing it again, haha. Really though - the triangle pose, when done correctly is AMAZING for opening your hips up and stretching! I'd definitely look into some basic yoga!
Edit: I used to do a sequence of only about 6 poses (including the triangle) on a daily basis, and it was really awesome for relaxing me and stretching! It also seems to build muscle, too, but instead of bulky muscle like weight lifting, your muscles develop more of a lean appearance.