We report measurements of electrical resistivity, thermopower, and thermal conductivity of highly C-60-filled single-wall carbon nanotubes and unfilled controls, from 1.5 to 300 K. The data suggest that the C-60 chains provide additional conductive paths for charge carriers, increase the rate of phonon scattering, and block interior sites from sorbing other gas molecules. (C) 2002 American Institute of Physics.