I think it's important to remember, though, that it's a lot less than it used to be. I'm never going to argue that mercury is innocuous, the mercury from my fillings has thrown my life into a tailspin that's lasted 2 years now, but for the kids who were vaccinated in, say, 2000, the amount of mercury they received is massively different than what is in the vaccines now (except the flu shot--that's the only one that kids would usually get that still has lots of thimerosol, right?).
If I'm talking to someone who's done some reading on the topic, I think it's especially important to make the distinction so that the rest of what I may mention isn't discounted out of hand.