Career switch to teaching - any advice about credentialing?

Thanks in advance for the feedback.

I have recently decided to seriously investigate a career change to become a teacher, most likely at the high school level (though I would consider other options). I have done a fair bit of research online and have also talked to several professionals, so now I’d like to see what others might have to offer.

Here are the pertinent details of my situation: I live with my family (wife and two young children) in New York state. We have no real ties to New York although we would consider staying here. We do have ties to California and Plan A currently calls for us going there sometime in 2010. However, we would really consider moving to any state and in fact even going abroad.

My existing credentials are a BS in engineering and multiple MS degrees, including geology and an MBA. My first choice of subject to teach is earth science but I am qualified to teach any science at the high school level and most subjects in math.

The advice I am seeking really boils down to this: What viable options are there for someone in my position to get credentialed to teach? I know reciprocity exists among some states and I also know that reciprocity is very complex.

Clearly, there are lots of other details that would be pertinent to the issue, but for now I’m hoping for some general advice. Thanks again!