What does it do?
This plugin is a replica of what is used in TapL's upcoming video 'Minecraft, But Your Inventory Shrinks...'. Every X amount of seconds (5mins by default), your inventory will shrink by one slot.

Installation
To install, just add the InventoryShrink-1.0.jar file to your server's plugins directory. Once the plugin is loaded and the server starts with it, a configuration file will be generated. In there, you can change the frequency of the shrink.

Commands
/invshrink - <on/off/toggle>.

Note
This is a plugin that requires a server, not a mod. You can't use this in a single-player world.