I have a b.s. in math, anyone know of any interesting jobs besides teaching, actuary?

I took a class in nonlinear dynamics and found it really interesting, I could potentially see myself doing some math modeling. I plan on taking a couple comp sci classes this fall at a community college just to diversify my coursework. I think I'd be interested in working for a company that helps the environment. Are there any interesting companies that work in the green energy industry/ model environmental processes? Also, are there any grad school programs that would make me more marketable?