  In the context of current particle physics theories, it is quite likely that
topological defects may be present in our universe. An observation of these
fossils from the early universe would lead to invaluable insight into cosmology
and particle physics, while their absence provides important constraints on
particle-cosmology model building. I describe recent efforts to address
cosmological issues in condensed matter systems such as He-3 and a possible
solution to the magnetic monopole problem due to defect interactions. (Invited
talk at the 1997 RESCEU Symposium, University of Tokyo.)
