What is GMmod? Its light and small plugin allowing you to disable selected functions if a player has creative gamemode. All is controlled by permissions. Wrote and tested on CraftBukkit 1.7.2 The plugin is working well for me, but it's not fully tested yet. Chat prefix and deny messages are configurable! (check config.yml)

Using permissions you can block access to:

Items dropping
Chests
Dispensers
Enderchests
Droppers
Hoopers
Brewing Stands
Chest on carts
Beacon
Anvil
Furnaces
Monster Eggs

Permissions list: === (all permissions are obvious)

gmmod.gmmod - /gmmod (default for all)
gmmod.reload - /gmmod reload
gmmod.bypass
gmmod.drop
gmmod.container.chest
gmmod.container.dispenser
gmmod.container.enderchest
gmmod.container.dropper
gmmod.container.hopper
gmmod.container.brewingstand
gmmod.container.storageminecart
gmmod.container.beacon
gmmod.container.anvil
gmmod.container.furnace
gmmod.egg - spawning mobs
gmmod.* - all of above

Configuration

Download latest plugin release
Copy it to your plugins/ folder
Reload or restart the server
Add permissions for users you want to have access to something.
Reload your permission plugin (I recommend PEX, in this case you do /pex reload)
Download config for your language and replace it (plugins/GMmod/config.yml)
Reload GMmod using /gmmod reload
Done!

What am I planning to add?

Blocking item frames (don't know how would it be working, we want our builders to have access to item frames)
Permissions for spawning selected mobs using eggs.
Should I make it configurable for survival GM too?
You tell me

Language support:

http://dev.bukkit.org/bukkit-plugins/gmmod/pages/languages-support/