We present results of Monte-Carlo simulations for finite 2D single and bila
yer systems. Strong Coulomb correlations lead to arrangement of particles i
n configurations resembling a crystal lattice. For binary layers, there exi
sts a particularly rich variety of lattice symmetries which depend on the i
nterlayer separation d. We demonstrate that in these mesoscopic lattices th
ere exist two fundamental types of ordering: radial and orientational. The
dependence of the melting temperature on d is analyzed, and a stabilization
of the crystal compared to a single layer is found.