This plugin logs the chat in a sperate logfile.
You can choose if it should log connects and disconnects, hourly the active players and if the plugin is activated/deactivated.
You can also choose the time format.
I coded this plugin because It was hard for me to read out the text messages out of the server.log. Especially the color codes of ChatManager (PermissionsEx) make it hard to read whole dialogs.
So if you want to control your chat (there are enough reasons for doing this) then you can use this plugin.
Maybe I will add /pm /msg observation later but since I don't need it you should let me know if you want that.