I'd love a real-time petition app. The idea would be to be able to create a petition to change something as the need arises and to alert others to sign it. So I'm walking down a sidewalk and come to a dangerous intersection; I'd launch the app and start a petition to get a stop light. All the other app users who live in my area would get a notification saying I started a new petition they might be interested in. Then, they could all "sign it" via the app, there would be some indication of progress, and once there are enough signatures, the petition would make its way to the local city council.