WINDOWS FOR ART AND/OR PROMOTION
Most downtowns have windows begging to be utilized as art or for information. In my current community (Lake Geneva, Wisconsin), the "Riviera Building" is the departure point for various boat cruises on Geneva Lake. One of the windows at the "Riviera" (in a supply closet) faces the boat launch where hundreds of people walk by every day. After removing bugs, cobwebs and cleaning the glass, this window was utilized to tell visitors of upcoming events within the community.
Minimial effort and upkeep should make this "low hanging fruit".