In this talk I will present an application of the level set method to problems in thin film deposition. The regime of particular focus will be problems where the diffusion rate of adatoms is orders of magnitude greater than the deposition rate. Under such conditions, the adatoms essentially stick immediately to an appropriate site once they strike the crystal surface. At the heart of the simluations is an algorithm for quickly computing the mass flux at the boundary of a domain , given an initial distribution of mass in the interior of which then undergoes rapid diffusion. I will also give an introductory level description of the level set method and how it is used in this context. Finally, I will give a few examples of different models for which this algorithm can be used.