The technology used the create these new onboard nitrogen inerting systems is Hollow Fiber Membrane technology.
Here's a link to an explanation of this technology.
IGS Generon System
With all of the discussion of missiles and terrorism in this thread, no one has mentioned that this technology makes airliners safer in today's higher threat environments. The US military has been using nitrogen inerting in aircraft since WWII, to help prevent fires and explosions when fuel tanks are hit.
Here's a link to an FAA article on this technology:
FAA Fuel tank inerting
Here's a quote from this article that illustrates the protection offered to an aircarft that's being fired upon:
What is a fuel tank inerting system?
An inerting system replaces the oxygen in the fuel tank with an inert gas such as nitrogen, preventing the potential ignition of fuel vapor.
Inerting systems have been used on military aircraft since World War II. Until now, inerting of the fuel tanks has been used to minimize combat explosions and battle damage. On high-speed airplanes such as the XB-70, an inerting system was used to prevent ignition of the fuel due to the heating effects of supersonic speeds.
Many different techniques have been used in the inerting systems on military aircraft. On World War II-era airplanes, engine exhaust was typically used to produce the inert gas. More recently, nitrogen has been used to render the fuel tank inert. Various techniques exist for separating nitrogen from air for use in inerting, the simplest and most reliable being the membrane technology that is used in the FAA-developed inerting system prototype.
This technology is a good thing, both to prevent future fuel tank explosions, and to help you survive if someone fires on your aircraft.