Various aspects of charge and exciton transport through thin films of organic semiconductors have been investigated over the past two decades; however, analogous details about the transport of electron spins remain unknown. The primary goal of our research program is to establish the structure-property relationships underpinning spin-charge and spin-exciton interactions in the condensed phase. In particular, we functionalized thiophene and phthalocyanine skeletons with stable radicals (spin ½ organic materials) and characterized how the condensed phase charge and exciton transport properties of the parent thiophene and phthalocyanine semiconductors are affected by the presence of a spin ½ moiety. Establishing these fundamental relationships is the first step in using radical-functionalized thiophenes and phthalocyanines in nanostructured spin valves and other similar spintronic devices. Preliminary electrical characterization of simple sandwich-type spin valves containing radical-functionalized organic semiconductors will also be discussed.