  After reviewing recent work on the dynamics of young supernova remnants
(YSNRs) and discussing how YSNRs can be used as physics laboratories, I discuss
several challenges: Where are the very young SNRs in the Galaxy? Can very young
SNRs produce gamma ray bursts? The Connections Challenge: Can one infer the
nature of the supernova and its progenitor star from observations of the YSNR?
