If you want to see what's going on at an atomic scale, you can't use a regular microscope -- atoms are smaller than the wavelength of visible light. Instead, nanoengineers, physicists, and others interested in mucking about in the realm of the very, very small use atomic force microscopes, or AFMs. AFMs build images by touching the tip of a probe -- just a couple of atoms across -- to the object to be imaged; the motion of the tip as it runs across the surface gets converted by computer to an image. Traditionally, this process is very slow, on the order of about one picture every ten milliseconds.
MIT researchers have now figured out a method of capturing the images in microseconds -- fast enough to create time lapse movies of nanoscale motion. Why is this a big deal? Because this enables researchers to monitor microscopic bits of engineering (like microfluidic pumps), keep tabs on the function of nanotechnological devices, even capture movies of biological activities at the sub-cellular level. Imagine a movie showing the replication of DNA.