I think H Ludi Tyler is exactly right. The way to get 'city' folks interested in to do it well yourself so they can see it as something they may want to try. I know a couple who do 'permaculture' and 'green building' tours on their place. They built a strawbale house, and they have what I would call a weed patch. Mostly well-off college aged people come and oh and ah and think it is wonderful. The place is a dump. Most people would never want their places to look like that. Most people would call somebody if their neighbors place looked like that. I think we need to face the fact that the majority of the population is used to neatly manicured lawns, and anything that doesn't at least look tidy is going to be a shock to their system that they just aren't ready for. If you want to give tours, get your place ready for it before you invite anyone. Inspire others to want to do what you have done, not be glad that they don't have to live in such an awful place with weeds everywhere. To really make any kind of difference at all, a huge amount of people are going to need to want to do it. So you really do need to appeal to the majority, and see it from the perspective of city people, who have probably never even had dirty hands before. Truly a daunting task...