For fans of the Terminal, Mountain Lion brought some new command-line utilities. Perhaps the most notable is fdesetup, which Apple explains briefly: "fdesetup allows third-party management tools to enable FileVault, determine encryption status, capture and manage recovery keys, and add users to a FileVault-encrypted system as well as synchronize directory-based user authentication credentials with the local credentials for FileVault access."
Apple provides a 'man' page for fdsetup, but if you want more information about it,
