The Arcadian alphabet was invented to write Arcadia, an invented language used in the computer game the 'Skies of Arcadia'. The alphabet is used to write inscriptions throughout the game.
Information about the Skies of Arcadia game
http://en.wikipedia.org/wiki/Skies_of_Arcadia
http://arcadia.island.free.fr/
Font for Arcadia (La police d'Arcadia)
http://arcadia.island.free.fr/media/down-divers.php