More feet than that because they, too, will educate others.
It would take time and effort, but we could sell local ads to be on the shirts along with the catch phrase regarding the dunes/cliffs. Of course SoWal.com would be stamped on all of the shirts. If you have 3-5 different catch phrases, you could encourage people to purchase more than one shirt. Shirts could be sold for $3 over costs to encourage everyone to buy at least one, with all proceeds going towards the costs of the marketing materials. This would have to be done on a voluntary basis. We could even have a T-shirt design contest, which was promoted in local papers and at local businesses. Blah, blah, blah. I am reading some great ideas on this thread, and mine are just a bit of things which I see other events already doing.
We've got lots of community minded people and I think what is being proposed requires a group of people (a committee, a coalition, an association, whatever) that are willing to spend a little time promoting the issue. It doesn't have to be many. It's a good cause. Local businesses will care and support it and hopefully local government will get on the bandwagon a little more agressively.
A brochure for rentals is a given. As someone said, we could just circulate one that could be photocopied at first unless we had a printer help out.
Billboards are expensive but maybe down the road with any proceeds from sales of shirts, caps etc
A t-shirt design or slogan contest would be great because vacationers read the walton sun and the beachcomber so just the search for the slogan will get some awareness. The group could do a panel at Via Colori. That vacationers channel might put a little cut about the dunes, who knows until we ask. I think it needs to be an ongoing campaign and will gain momentum and support if it can get off the ground. It's a good cause and what we're doing now isn't working.
T-Shirts could extend beyond our area because if we got them in the right places, people would buy them as souveniers to take home and get the word out in Atlanta, B'ham etc (before they get here). I'm thinking of having some made and giving them out to my clients.
A home falling off the dunes would have definitely have a great impact with either slogan. Moonwalk not Dunewalk is great! The LARGE statute citation is good too but kids, teens and perhaps some adults are clueless what a statute is.
Rent a cops - no way. It goes against everything we are here. We're still a place where you can leave your bike out or leave your door unlocked. We want people to come here and chill out not freak out about their cooler of beer on the beach every time enforcement drives by. On Clearwater beach, there's police all over hassling people about stupid little things. 30A has a deserted tropical island feel and an obtrusive presence of law enforcement kinda kills the gilligans island feel.
Same with the prisoners.
Work details are prettty common up here, particularly along interstates (litter picking). Whack two birds with one rock. Print "I walked on dunes!" on front and back of orange suits. 

Love the Slogan "I walked on the dunes" with somebody in stripes. Maybe a Pelican
I've got no problem with prisoners on the Interstate but I dont want them seeing my home, I dont want to see them and I certainly dont think moms with their cute little 5 yr old blonde daughters are gonna want to see them as they step out of their $5,000 a week rental home in their bikinis. :nono1: