Carbon nanotubes exhibit remarkable physical properties and there is considerable interest in using them as nanoscale building blocks for a new generation of applications. Despite this promise, fundamental issues related to the dispersion, orientation, and manipulation of individual nanotubes remain unresolved and efficient bulk processing schemes do not yet exist. Our group uses a variety of methods to measure the structure and rheology of dilute, semi-dilute, and concentrated carbon nanotube suspensions and melts, with our results having profound implications for the flow processing of nanotube based materials. I will discuss some of our findings in the context of potential applications, as well as our current efforts to quantify and control the dispersion of single-walled carbon nanotubes using biological dispersants such as single-stranded DNA.