As length scales shrink and demands on magnetic materials increase, engineers are increasingly looking toward molecule-based materials to develop the next generation of magnetic devices. These materials show promise for specialized applications, including magneto-optic recording, magnetic shielding, components of lightweight transformers, generators and motors, photomagnetic switches, sensitive molecular sensors, and spintronic devices. The appeal of molecule-based magnets is a result of their highly tunable nature, transparency, low density, moderate solubility in organic solvents, and facile preparation under mild conditions. This is in contrast to the current technologically useful magnetic atom-based (inorganic) materials, which have greater densities and require high temperatures and/or pressures to prepare them. Through molecular synthesis, organic chemistry provides the ability to fine-tune structures and properties to a much greater extent than is possible for inorganic materials. The possibility of combining multiple physical properties, such as optical/magnetic, conducting/magnetic, and so forth, has prompted the quest for hybrid materials, many of which consist of polymeric molecular magnets.