  We discuss the essential features of baby-universe production, starting from
a description of black holes and wormholes, in terms of the causal structure of
spacetime, and following a qualitative review of the connection between vacuum
decay and inflation in early universe cosmology. Related open questions are
also addressed, especially in connection with the possibility that baby
universes could be formed within our present universe - either in a future
particle accelerator, or spontaneously.
