The current situation in Japan from the earthquake, tsunami and now the radiation from the nuclear power plants is overwhelming.

Does praying do anything in these kinds of situations? How does one pray for such a thing?

We know volunteering, donating, etc., helps as best it can in the real world. Does praying help? Can it stop such things as nuclear reactors from exploding? Surely, praying does something for people doing the praying on a psychological and spiritual level, but is having an external effect just wishful thinking with no real tangible result on the focal point? In the same train of thought, what about casting a positive spell?