I've had a few funny experiences. While I have never seen another RF user, I bumped into a Large Format photographer. When I asked him what kind of camera, the first response was "it's a film camera". I showed him my Leica and said "yeah, I shoot film too." He warmed up and talked about it. It was an old Speed Graphic (graflex?) camera.
Last spring while walking through Harvard Square, I had my R-D1 slung around my neck, and a fellow had noticed it from across the street. As soon as the cross walk light went on, he came over and we talked for about 30 minutes. At first I think he thought it was a Bessa and commenting on how he liked RFs in general. I then flipped the screen and his eyes almost popped out of his head. He used to shoot Leica's, but then switched over to a Canon 10D with a fixed 50mm. He liked the immediate feedback, but overall missed the feel of the RF. He loved the R-D1 though. We ended up talking about the benefits of film and he was partly the catalyst for me picking up a Leica and shooting/souping film.
Since then, I've been stopped randomly and people have commented on the Leica or R-D1. Still haven't seen another RF shooter though.
Not to derail this topic, but what are peoples experiences in camera shops? In certain stores, I've noticed extra attitude if I have an RF slung around my shoulder and I inquire on some film or dev products. Usually it is from college kids; do they feel intimidated by film or something?
-Paul