Bukkit

• - Exp Can be set to any number
• - Gamemode can be changed to Survival or Creative
• - Exp can be reset (Back to 0)
• - You can heal yourself
• - You can feed yourself
• - Make yourself invisible to a player
• - Kill a player
• - Set a player on fire!
• - Kill all mobs!
• - Set your health to any number ( At or below 20)

None so far :)