This chapter presents an overview of Raman studies performed in scientists' laboratories on solution phase and related nanotube samples. Raman spectroscopy is a powerful, multifaceted technique with wide-ranging applications in carbon nanotube studies. Resonance Raman excitation profiling becomes a useful means of mapping out transitions of different chiralities for oped nanotube samples. The single-nanotube Raman studies demonstrate well that development of new techniques and probing of new sample types will invariably lead to new insights into nanotube chemistry and physics. The main barrier to the extensive application of single-walled carbon nanotubes is the inability to manipulate according to electronic structure. The chapter describes examples of practical uses of Raman spectroscopy for sample evaluation and monitoring of nanotube reaction chemistry. The experimental Kataura plot can be used to determine which nanotube diameters are in resonance with a particular excitation wavelength utilized in Raman spectroscopy.