I dont have time to read the whole of this very interesting but LONG article to see if he mentions airbag helmets.
I am skeptical about how well these airbags protect one's face, but its an interesting new take on protecting your head.
http://www.hovding.com/en/how_it_works?/en/how
They also have airbag jackets for motorcyclists
http://www.bikebone.com/Air-Vest-Motorcycle-Airbag-Hit-Air.h...