I have been using POPULUS by Don Alstad (Univ. of Minnesota) in an
introductory populatiog genetics course. It was extremely useful to
show the effects of drift, selection and population subdivision.
The program is free and may be downloaded via FTP from the server
ecology.ecoloy.umn.edu directory /pub/populus.
It is easy to use and has nice graphical features.
Hans Solkner, Univ. of Agriculture, Vienna, Austria
soelkner at mail.boku.ac.at