We discuss some general aspects of acoustic black holes. We begin by
describing the associated formalism with which acoustic black holes are
established, then we show how to model arbitrary geometries by using a de Laval
nozzle. It is argued that even though the Hawking temperature of these black
holes is too low to be detected, acoustic black holes have interesting
classical properties, some of which are outlined here, that should be explored.Comment: 13 pages, 9 Figures, ReVTeX4. Based on a talk delivered at the Fifth
Meeting on New Worlds in Astroparticle Physics (Faro, Portugal, 8-10 January
2005). Updated references and overall improvemen