The Public Works departments of Cambridge, MA and St. Paul, MN have a Sidewalk Poetry Program that annually requests residents to submit original pieces of poetry to be stamped into fresh cement. A group of individuals then reviews the poems and select a few to be used. The cost of this program is minimal: the poetry stamps would be used only on sidewalks that are being repaired or on new sidewalks. This means the cost would be the stamp and a few moments of the public works employee’s time to place the stamp in the sidewalk.
Another idea would be to paint existing sidewalks with water-reactive paint (the type used at Decatur WAY) with stencils for the poetry.