Basically this plugin will automatically dispatch a command after a player has played for a certain amount of time. For the config it would be cool of you can configure the amount of time they need to be on and the commands that will be dispatched.
You will find this function within OnTime http://dev.bukkit.org/server-mods/ontime/ See here for more specific information http://dev.bukkit.org/server-mods/ontime/pages/rewards/#w-command-rewards-notes
