The following poster was found in the bathroom of a local eating establishment:
Although the placement in the bathroom is an interesting touch, that is not why I think it is particularly creative. When Clarion River Organics printed these posters, they left a space for "pick up at" blank to be written in for each poster. So when I look at this poster, assuming I live in the neighborhood, I know exactly where I can pick up my share. This is really smart because many people will choose a CSA largely on the basis of pickup proximity.
With the wonders of mapping software on phones, they could take this the extra mile and put the distance from this location to the drop-off (ie 0.76 miles from here) in case it is not immediately obvious to the reader where Hampton Avenue is.
Try this with your posters and let me know how it works!