Using modern growth techniques, it is possible to fabricate semiconductor systems which are very good approximations to the "textbook" examples of first-semester quantum mechanics. Confinement in one spatial dimension is realized in quantum wells while higher degrees of confinement can be achieved in quantum ``wires'' or ``dots''. I will talk about some experiments in which electrons and holes are confined to quantum wells or dots in which magnetic ions have been substituted in a II-VI semiconductor alloy. It is possible to couple optically to the spin of the confined carriers, thus probing the magnetism of these low-dimensional systems, which can be strongly spin-polarized.