The neural interface
The neural interface can be put in your armour slot and interacted with like a computer. Modules and other peripherals mounted on it get full access to the player.
Modules
Plethora comes with several other modules which allow interacting with the world
Laser
You can fire lasers
Controlling mobs
You can attach the neural interface to mobs too: and control their movement.
One simple request
Squid with frickin' laser beams attached to their heads!