Bukkit

Permissions:

Lock.Toggle: Acess to /lock on/off (or just /Lock for toggling on/off)
Lock.Join: This is the permission to join while the server is locked
Lock.Time: Acess to /lock on time m/h/d (m for mintues, h for hours, d for days)
Lock.Help: Access to /lock help
Lock.ToggleMotd: Access to /lock LockedMotd on/off
Lock.setLockedMotd: Access to /lock setLockedMotd Motd
Lock.setPrefix: Access to /lock setPrefix Prefix
Lock.setKickMessage: Access to /lock setKickMessage Message