  Besides being a fascinating class of new materials, magnetic molecules
provide the opportunity to study concepts of condensed matter physics in zero
dimensions. This contribution will exemplify the impact of molecular magnetism
on concepts of frustrated spin systems. We will discuss spin rings and the
unexpected rules that govern their low-energy behavior. Rotational bands, which
are experimentally observed in various molecular magnets, provide a useful,
simplified framework for characterizing the energy spectrum, but there are also
deviations thereof with far-reaching consequences. It will be shown that
localized independent magnons on certain frustrated spin systems lead to giant
magnetization jumps, a new macroscopic quantum effect. In addition a
frustration-induced metamagnetic phase transitions will be discussed, which
demonstrates that hysteresis can exist without anisotropy. Finally, it is
demonstrated that frustrated magnetic molecules could give rise to an enhanced
magnetocaloric effect.
