Carbon nanotubes are one of the most talked one dimensional nanomaterials for over past two decades, and are considered to be important materials for both fundamental and applied research by virtue of unique mechanical and electrical properties. In order to justify their potential it is important to investigate physical properties of these materials. This book includes a description of one step technique to synthesize fairly good quality multiwall carbon nanotubes (MWCNT); the Raman and electron microscopy characterizations of as-synthesized MWCNT revealed the high quality and aspect ratio, respectively. The low temperature charge transport studies of MWCNT and MWCNT-based composites resulted interesting results, namely - metallic transport of MWCNT and weakly temperature dependent conductivity of MWCNT-polystyrene composite at the percolation threshold. Further, encapsulation of iron nanoparticles within nanotubes induced ferromagnetic properties; unprecedented observation of non-monotonicity in the coercivity as a function of wt fraction of MWCNT in polystyrene is quite interesting result.