  The yrast spectra (i.e. the lowest states for a given total angular momentum)
of quantum dots in strong magnetic fields, are studied in terms of exact
numerical diagonalization and analytic trial wave functions. We argue that
certain features (cusps) in the many-body spectrum can be understood in terms
of particle localization due to the strong field. A new class of trial
wavefunctions supports the picture of the electrons being localized in Wigner
molecule-like states consisting of consecutive rings of electrons, with
low-lying excitations corresponding to rigid rotation of the outer ring of
electrons. The geometry of the Wigner molecule is independent of interparticle
interactions and the statistics of the particles.
