Probing order in nanotube systems is of fundamental importance in devising applications of these tubes in field emission applications as well as for components of composite materials. We use near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to qualitatively and quantitatively study the degree of order and alignment in a wide range of carbon nanotube-based systems, including single-walled carbon nanotube (SWNT) powder, SWNT films, and aligned multiwalled carbon nanotubes. The results are compared to analogous data obtained from a highly ordered pyrolytic graphite (HOPG) sample.