Bukkit

/tip [message] (Sends a tip message in chat)
Permission: ch.tip

/broadcast [message] (Sends a broadcast message in chat)
Permission: ch.broadcast

/important [message] (Sends a important message in chat)
Permission: ch.important

/clearchat (Clear the chat)
Permission: ch.clearchat

/weather [sun,storm,rain] (Changes the weather)
Permission: ch.weather

/time [day,night] (Changes the time)
Permission: ch.time

/fake [join,leave] (Sends a fake join/leave message)
Permission: ch.fake

/hat (Set a block as your hat)
Permission: ch.hat

/heal [player] (Heal a player)
Permission: ch.heal

/msg [player] [message] (Sends a private message to a player)
Permission: ch.msg

/ip [player] (Get a player's IP)
Permission: ch.ip

/kick [player] [reason] (Kick a player with reason)
Permission: ch.kick

/fly [player] (Enable/Disable fly for a player)
Permission: ch.fly

/gamemode [0,1] (Turn gamemode to CREATIVE or SURVIVAL)
Permission: ch.gamemode

/ban [player] [reason] (Ban a player with reason)
Permission: ch.ban

/helpop [message] (Sends a message to all Admins)
Permission: ch.helpop
ch.helpop.receive

/chreload (Reload the config)
Permission: ch.reload