This is slightly old news but over at Lisp, The Universe and Everything there's a nice interview with Juan José García Ripoll, the developer of Embeddable Common Lisp. The thing about Ripoll is that he's not a programmer1; he's a physicist who got into Lisp because he wanted a better way of handling the simulations that were his bread and butter.
It's interesting that non-programmer scientists, like Ripoll, would turn to what almost everyone considers one of the hardest programming languages to master. Of course, those of us who have embraced Lisp have no difficulty understanding this. Lisp allows the researcher to quickly represent his physical models without worrying about programming minutia. As Ripoll recounts, he was able to leverage the Lisp bignum capabilities to solve a 3-SAT problem in an afternoon and to produce an executable that ran faster than the problem's C++ prototypes.
I like Ripoll's story because it demonstrates how powerful Lisp is. If you're a physicist faced with solving problems like his and your first thought is Fortran, you're going to get eaten alive both by Fortran and by guys like Ripoll who leverage the power of Lisp.
If you're a scientist using computer modeling, it would be well worth your while to take a look at Ripoll's interview. If you're a Lisper, you'll love Ripoll's story of problem solving with Lisp.