A plugin that allows my Mod's and Admins to have a seperate chat channel to the rest and can have colour codes so its different from the rest of chat. Commands: /mod - mod chat /general - generalt (normal) chat permissions: mod.chat
This may be a little more advanced then what you want but it has a bunch of channels like admin,Mod,Local,Global(general) and lots more, Give it a shot see what happens http://dev.bukkit.org/server-mods/herochat/ Hope this helps - Pro