I read a post over at Nano Nook that deals with all sorts of cool topics at the nanoscale. There is a post there that describes an atomic force microscope (AFM) that can be used to measure the surface topography and even chemical composition using an oscillating tip that is scanned across a material. The technology uses a laser to accurately measure the oscillation phase (timing of oscillations) and amplitude (the distance of vibration) of the tip. Take a look at Nano Nook's post for a nice diagram and more information! Also check out his links that give even more detailed information if you are intrigued.