I wonder how feasible it would be to get some of those plastic signs--the kind people use to show support for political candidates and such--custom printed to say something along the lines of
"This sign isn't here to sell you anything, or to convince you of anything; it just wants to tell you to have a nice day"
@JulieSqveakaroo I hope they turn out to be cheap. If we could get a few dozen for $20 or so it might be a worthwhile thing to do, just get some of those and plant them around the city.