I found this article on bike helmets and the relative safety of biking. I ride my bicycle to work most of (read: for the dry parts of) the spring, summer and fall. The tone of the article is one of “The Big Helmet Lobby is screwing us over!”-type-paranoia but the statistics sound fairly solid.
Apparently, being in a fatal bicycle accident (when you’re a sober adult) is about as likely as experiencing a fatal lightning strike. Now, I know some folks who’ve been struck by lightning (though none have died from it), so I won’t consider this completely impossible. But it sounds like, the odds of bicycle fatalities aren’t significantly effected by helmet use.
And I’ll probably continue to wear a helmet, since it’s the law, and all. (Though it is rarely enforced, and pretty silly, not to mention the-not-coolest-looking I’ve ever worn.)