While most of our knowledge of protoplanetary disks is based on single snapshots of many systems, their evolution is in fact highly dynamic on short timescales. Previous surveys have found that the majority of young stellar objects are variables in the infrared. This variability has the potential to teach us about the detailed structure of circumstellar disks, in a way that is difficult given the resolution limit of most current telescopes. I will present results of a survey of a nearby young cluster using the Spitzer Space Telescope covering daily to weekly fluctuations. I will discuss the properties of the variability, as well as potential models for explaining the observations in terms of large structural perturbations within the disk.