Critter has it right.
It's important to not get distracted from the goal.
The goal is to WIN.
Sometimes, folks on our side think the goal is to get anti-gunners to ADMIT that we are right.
They will not. And, even if they did, that does nothing for us.
The only way to win -- let me repeat that -- the ONLY way to win is to move public perception. This is done in 100 or 1000 ways. Almost always, these are gentle, subtle, persistant, and consistant.
Holding shooting matches to raise money for breast cancer research, working with a local woman's group, and getting good local PR is an example of how to move the needle of public perception just a smidge.
Taking someone who does not shoot to the range, introducing them to the sport in a friendly way, is effective.
Never mentioning "Hitler," "Communism," or "Nazis" is a good start. As soon as you start the "that's what Hitler did" talk, you lose, and you convince someone else that we are crazies.
Putting together a team of "I'm the NRA" T-shirt wearing workers on a Habitat for the Humanities project?
Inviting politicians to the range (make sure the media is there).
One good guide that every "activist" should have is "The Citizen's Guide to Fighting Government."
http://www.amazon.com/Citizens-Guide-Fighting-Government/dp/0915463636
In most cases, it is best to ignore antis. Focus on the people you want to reach -- the uncommitted public.
Shove an evil-looking rifle in their face, and they will call the Brady Campaign to sign up. Take 'em to the range and let them shoot a Ruger 10/22, and they'll love it. THEN you can gently explain that this is a semi-auto, etc.