I consider myself fortunate to have taken the advice of the knowledgeable members of this forum.  I also chose a DOT helmet to ride with - right before my accident in 2010.  A truck turned left at a green light while I was still going straight.  Since his was a very gradual turn, he hadn't slowed down much at all, so he pretty much blasted me off my bike and sent me tumbling through busy morning rush-hour traffic.  I was VERY lucky that he was the only one who hit me (as far as I know).
Now, at the time, I was wearing my helmet and my very-stiff biker jacket.  So when I came to in the hospital, from the waist up all I had was whiplash, deep bruising, lacerations, and multiple dislocations.  BUT, from the waist down, I had a shattered tibia & fibula, torn up knee, cracked pelvis, broken tailbone, and more dislocations.  And I later got a staff infection shortly after the second operation.
But the hospital staff saved my helmet along with my other belongings.  And the surgeon got to see it before I did, and it was his opinion that I owe my helmet my life.  
I still have it in the back room.  Of course I don't wear it (I have a new one pretty much just like it).  But I can't seem to bring myself to pitch it just yet.  And I've had the opportunity to show it to a couple kids who asked me if I thought helmets did any good.