Magnetic nanorods are attractive materials enabling assembly, ordering, control, and reconfiguration of different magnetic lattices within milliseconds. MilliTesla magnetic fields are sufficient to manipulate with these nanorods. In this talk, a few examples of applications of magnetic nanorods will be shown. First we will discuss the remote controlled rotation of magnetic nanorods providing a new nanoscale tool to probe different properties of liquids and solids at the micrometer scale. The current challenge of the in situ characterization of minute amounts of fluids rapidly changing their rheological properties will be addressed. Basic theory of Magnetic Rotational Spectroscopy for rotation of a magnetic nanorod in non-Newtonian fluids will be introduced and specific features of rotating nanorods will be explained. Then we will experimentally demonstrate that magnetic rotational spectroscopy provides rich physicochemical information about the gelation processes of polymers and sols. Recent progress in understanding of the basic physical principles of the nanorod alignment in thin films by external magnetic field and characterization of these films by magnetic rotational spectroscopy will be presented.