Amidst the swamp and scrub of central Florida, the Disney Corporation has built Celebration, an environmentally friendly place where 20,000 inhabitants can enjoy the old-fashioned virtues of small town America in a totally modern development. With newly-minted antique homes, a post office designed by Michael Graves, stringent regulations banning the hanging of washing outside and FOr Sale signs on lawns, and piped musak issuing from the palm trees that line its streets, no detail of Celebration has been left unplanned.