The effect is incredibly strong though. So much so, that when you take a photo, you sometimes look at the resulting image and go "Wait! What happened? Why is it so small?!?"
So, how do they get shots with a huge moon?
Two ways that I know of:
1) Simply fake it in photoshop. If you're doing an illustration, say for a halloween poster, this may be fine.
2) Want the real thing? Use the biggest lens you can get/rent and shoot from a long way away from your foreground subject. For example, shoot Seattle from across the Sound. Steve Carter did that with one of his shots, worked well.