Having been the recipient of a few insults myself, I have to say that it's a small price to pay for the ability to express my opinion.
I'm well aware that others may disagree with me - it's just a shame if some of those respond in an immature manner.
Best thing to do is ignore 'em and don't respond in kind: after all - if someone has a valid point of view they will stand by it and defend with a reasoned argument, won't they? So the insults are a form of admission of defeat.
So bring it on guys - but remember that insults always say much more about the insulter than the insultee.