For decades, the conducting polymer polyaniline was known as a material with an irregular granular morphology. Recently, a simple modification of the �conventional synthesis� based on rapidly mixing the reagents has proven to be an extremely effective way of producing high yields of uniform nanofibers. We have extended this technique to a series of mono and di-substituted analogs of aniline to examine the influence of ring-substitution on the nanoscale morphology of the resulting material. Scanning electron microscopy has revealed both discrete and interconnected nanofibers; nano/microspheres; and highly porous materials, depending on the monomer. Notably, the morphology of several of these materials is also strongly influenced by reactant concentrations.