Well, not to be out done, geeks have their own version for their own uses; an über meme called WarChalking closely related to War Driving. It seems to me that in the 'burbs (which is where I live), not many people are going to be willing to walk around chalking wireless access points, and who would see it anyway? And doesn't chalk seem to be a little transient for this use? But who cares about that when there's these "i plus points" all over the place.
In my community, there is a movement to get a Wide Area Wireless Internet Access Provider (WAWISP) put together. I suppose WarChalking that would be helpful, but the car reigns supreme in this area, so don't be shy people, chalk the street signs too; or better yet, a Giant-esqe sticker campaign.
(ps, again, this would be a prime TrackBack opportunity, but this time the site I'm referencing uses MovableType, but doesn't have TrackBack installed/enabled, so I'm just going to ping the TrackBack dev page for the hell of it.)