What someone should design is something like the avalanche airbag. It is a really expensive backpack for backcountry skiing that inflates when the skier pulls the ripcord. The big balloon helps keep their head above the snow and pushes them to the surface.
Well imagine the same sort of thing that inflates when it detects that you enter free fall (flying through the air and nothing resisting the force of gravity). It could stabilize your neck a bit and and cushion impact to your head, spine, and any vital organs. The large volume would also increase your drag and dissipate some of your kinetic energy as you fly through the air.
Last edited by Dan The Man; 04-12-10 at 09:59 AM.