There is a great deal of interest in understanding and controlling the chemistry of carbon nanotube sidewall functionalization. Enhanced solubility, improved formation of composite materials, controlled modification of the electronic structure, and increased hydrogen storage capacity are a few of the applications that this technology may impact. In this talk we will present scanning tunneling microscope studies of partially and fully fluorinated single-walled carbon nanotubes. In addition, we have imaged carbon nanotube sidewalls modified by various solution chemistry methods. Differences in electronic structure and surface coverage produced by each method will be discussed.