Howie, Don and all, I know this is a personal choice in those juristictions where we can choose, but personally I would never ride without a helmet. Some of what the guy says I agree with - better training, stiffer sentencing for dui, no eating, cell phone, etc, would make the road much safer. But what about single vehicle crashes like I had in MV. All this would not have helped me and without a helmet, well we won't go there.
The statement about Dale Earnhart is just plain wrong. He died because the g-forces ruptured his aorta as I recall. Had nothing to do with his helmet.
There is an impact standard (for D.O.T. and Snell) but the majority of motorcycle head injuries is NOT due to impact but rather injury to the brain as it shifts inside the skull and slides along the surface (which is not smooth and allows the brain to scrape inself on bony bumps). Purpose of helmet is that as the soft foam crushes it allows the brain to decelerate which helps reduce injury to it.
Somewhere I think on the site there was a posting of an excellent article by Prof. Harry Hurt in Motorcycle Consumer News, February 2005. I'll try to find the link and post it.