We have a mandatory helmet law here in Seattle. I personally have no problems with it. I don't view it as any different than the mandatory seatbelt law that we have here too. Of course I value my functioning brain and I wouldn't ride without a helmet on law or no law (nor would I ride in a car without putting on a seatbelt) so whether or not it is mandatory makes little difference to me.

The city makes an effort as well - there are several programs that provide free or low cost helmets - especially to low income children.