Microrheology is the study of the deformation and flow of complex fluids at the microscale. As a graduate student, T.G. Mason invented an approach in 1993 for deducing local and macroscopic viscoelastic shear moduli of complex fluids by measuring the thermal fluctuations of colloidal particles introduced as probes. This approach, later published in Physical Review Letters in 1995 with his advisor D.A. Weitz (PRL 74 1250), sparked the modern field of microrheology. We continue research on glasses using thermal microrheology; our group also uses laser tweezers to manipulate dielectric probe microparticles such as polystyrene spheres and wax disks in order to investigate non-linear rheological properties.