Within the past several years, advances in high-resolution electron energy loss spectroscopy (HREELS) have permitted the application to increasingly complex systems, "technical surfaces", which depart from well-characterized, smooth, single-crystal surfaces. These developments have tracked a series of improvements in instrumentation, with present generation spectrometers exhibiting limiting energy resolution below 1 meV at relatively high detector currents (10 pA, direct beam). This paper addresses recent progress in two of these areas : polymer surfaces and model-supported catalysts.