It is so funny that you should ask on this last night of ths particular project. Someday I'll explain.

I am misapplying this tool (from our friendly, socialistic, non-Libertarian CDC) at this very moment to run some crude statistical tests. It includes a module (and old DOS program really) called Statcalc that includes a sample size estimator. You may be able to just download the Statcalc bit.

Oh, do I wish we had money for SAS!