Special techniques are needed to reliably measure the ultra-thin film and interfacial properties. In this review several novel ultra-thin film techniques that were developed and/or adapted are discussed: Fowler-Nordheim electron tunneling current oscillations; spectroscopic ellipsometry (SE) a novel application of SE called spectroscopic immersion ellipsometry, atomic force microscopy along with fractal analysis. Recent results using these novel techniques are reviewed on ultra-thin SiO2 films for film thickness measurements, the kinetics of the initial regime of Si oxidation, and interfacial roughness and the effects of roughness on Si oxidation and interfacial electronic properties.