A company called Scent Sciences makes a system that adds scent to video games. ScentScape is a personal digital scent delivery system, and according to Gizmag:
the ScentScape system uses a combination of hardware, software & algorithms and chemistry - all covered by patents - to produce the smells. The system consists of a unit that plugs into a PC or gaming console via USB and generates smells using scent cartridges.
When you get a system, you get 20 scents that last for 200 hours, and you can control the strength of the smell through a control the way you turn the volume up or down.
Wiles says that gamers will also be able to use the company's SDK along with the ScentEditor application to create their own scent-enabled games. Players will even be able to share the code they have created with other gamers who have their own ScentScape system to allow them to enjoy their creation.
The company will introduce the ScentScape Gaming Suite in February.