It's very simple... A config file to disable commands in certain worlds. Ex: in world_1 you can use "/spawn"; in world_2 you can't.
MartySilverFox I suggest that you get an permissions plugin that gives the ability to use permissions per world. Or use the worldguard blocked-cmds flag
There's a plugin called bPermissions (yes, there's a "b" in bPermissions) that allows choosing per-world permissions. You're also gonna need bChatManager for the prefixes and suffixes. bPermissions : http://dev.bukkit.org/bukkit-plugins/bpermissions/ bChatmanager : http://dev.bukkit.org/bukkit-plugins/bchatmanager/