readFam() now has a parameter Xchrom which can be used to indicate that the markers included in the file are on the X chromosome
MPPsims() is more flexible, and allows subsetting of its output.
powerPlot() is more flexible and allows finer control of the plot contents
readFam(). It is more robust now, and fails gracefully in certain situations which cannot currently be handled (e.g. if the file contains twins).