Years ago, Saurabh Rindani and I had done a substantial body
of work on measuring, or atleast constraining the dipole
moment of tau-leptons using polarized beams. If an elementary
particle were to have a dipole moment, then it would be a
signal of CP violation (C=charge conjugation, P=parity).
CP violation todate has been observed in neutral meson
systems. Returning to our work, it has recently received
the attention of atleast one experimentalist,
see this talk.