I find when discussing the merits of helmet use, a lot of people reference helmets.org (aka the Bicycle Helmet Safety Institute)

The site mentions they are a group of individuals associated with the Washington Area Bicyclist Association, but really it's mostly just Randy Swart who does almost all of the work.

Anyway, it might be of interest to know that The Bicycle Helmet Safety Institute supports carefully drawn mandatory helmet laws covering all age groups because we believe they are needed to raise awareness that helmets save lives...

You also have to laugh (or you'll cry) when the site says,

We still see messages on helmets in Internet newsgroups that fall under the heading "helmet wars." They are mostly to or from a group of about a dozen people who oppose helmet laws.

Yeah. I don't know. It sure seems to me that there are a little bit more than a dozen people who oppose helmet laws.