I was jeered by a bunch of teenage boys while climbing Umbria Street in Manayunk last year. That's the closest I've come to being 'encouraged' on a ride.
Well, almost. Back in 2007 on a day of bike commuting, I was riding home atop my Navigator. Since I work second shift the return leg is at night, 11:00 PM or so. As I passed through Phoenixville, a car pulls alongside me and the passenger sticks his head out of the window. I was scared nearly to death, but he only wanted to ask a question:
"Guy, I saw you riding this same road this morning, and you are still out here. Is this a contest or something?"