I think somebody mentioned about being able to adobt an Iguana and most of the people will put there pets as well as there enclosures up for adoption as well. Here is a good adoption agency which does a real good job on trying to find good homes for there animals(as well as enclosures) and has people trying to find good home for there lizards all accross the states. Throughout most of the adds I have seen, I could say a good percentage includes the enclosure along with the animal.
http://members2.boardhost.com/gisadoptions/
Really worth looking at if you plan on owning an Iguana.