I used to joke about a cyclist being able to have an airbag for protection. But, in Sweden they have launched this product called a Hövding which automatically inflates after detecting a collision.
Wouldn’t protect you from birds diving out of the sky at you though…
Related
Reasons to wear a cycling helmet
Should cycle helmets be made compulsory
Dave Moulton’s take on this: http://davesbikeblog.squarespace.com/blog/2010/10/25/airbags-for-cyclists.html