Ji Lee printed 50,000 speech bubble stickers and placed them on top of movie posters, ads and signs all over New York City. Passers are invited to fill them in. He then photographs the results and puts it on his website.
"Date me! (please)"
What a great way to get people to interact! This is a great advertising medium idea waiting to be explored. True, you can't control what people write, but people will definitely remember the poster.