  We present three new methods for determining the age of groups of
pre-main-sequence stars. The first, creating empirical isochrones allows us to
create a robust age ordering, but not to derive actual ages. The second, using
the width of the gap in colour-magnitude space between the pre-main-sequence
and main-sequence (the radiative convective gap) has promise as a distance and
extinction independent measure of age, but is as yet uncalibrated. Finally we
discuss tau-squared fitting of the main sequence as the stars approach the
terminus of the main sequence. This method suggests that there is a factor two
difference between these "nuclear" ages, and more conventional
pre-main-sequence contraction ages.
