I have collected brochures from Social Services on child abuse, elder abuse, how to get legal help, where to go if you are an abused woman, etc, and stuck those brochures in the doors of Kingdom Halls.
Rationality rarely works when confronting JWs about why they are one. I think that making JWs aware that there really is help for them on the outside appeals more to their emotions than their (lack of) rationality.
I usually don't bother tackling their theological errors. Most people who are JWs make the choice to be one do so because of an emotional reaction, not a rational reaction. I used to get into theological debates with them but now I just talk to them about their child abuse issues or the blood transfusion ban.
All of my friends and most of my acquaintances know that I am an ex-JW. Whenever religion has come up in the conversation, I always self-identify as a cult survivor. Most people are quite alarmed about the inside, insiduous practices of the JWs - they just think that they are those annoying people who knock on doors and don't celebrate Christmas or birthdays.
I have plans to do my best to stop the JWs from setting up a table at the university this coming semester. It won't be hard to get the women's rights groups to make a stink about the JWs recruiting on campus once I show them videos of Jackson's testimony revealing how JW women are denied basic human rights. If that doesn't work, I will print off the extensive list of Religious Studies classes that the university offers and give it to the JWs that man the tables. If they want to claim that they are "Bible educated" then it might be a good idea for them to see what "the world" has to offer in religious/Bible education - which far surpasses the WTS education.
I also sometimes do things like send off emails to international organizations such as Amnesty International and children's rights groups. Every once in a while I get the urge and I do another email campaign.