I think the more we speak up the better. Obviously at the right time and place but the people that don't own guns (and the anti's) need to see that there are perfectly normal people that own guns and that they are all around them. They need to see that not all gun owners are redneck anti-gubment hicks intent on shooting up a crowd whenever we feel like it.
That is why I'll occasionally post on facebook that "boy it's crowded at the range today" or "good day to take my daughter to the range" or similar benign comments. I think the more people know we are out there and are not a threat to them, the better.