A plugin where on Christmas everyone gets a gift. (editable in the config) Maybe have the plugin installed before Christmas and it will "watch" the players. If the players swear at all they will get coal on Christmas and if they swear a bit they get something good and if they don't at all they get the best gift. The gifts are all configurable.
There is one There is one http://forums.bukkit.org/threads/the-christmas-plugin-beta-available.44128/ and also a halloween one http://forums.bukkit.org/threads/un...v1-1-new-world-and-trick-or-treat-1337.43122/