Me too. Slid into a curb and cracked the helmet. Can't be completely sure but I figure this would otherwise have caused some serious head damage.

And on the hearsay side, I had a chance to speak with the head of neurosurgery at a major trauma centre. He is passionate about the benefit of bike helmets but, really, what would he know? Probably better to trust contrary opinions of random internet dudes.

In any event, helmet laws aren't the answer. We have such a law for people under 16 and, ironically, this is the group that rarely seems to wear a helmet at least not when they're out of their parents' sight/control.