Yeah, it's definitely hit-or-miss. The guys I saw usually didn't have the camera pointed at their faces... But the Norwegian kids made it all worth it. First they made me play them a song on my guitar, then I asked them to sing -- they burst into a song in four-part harmony. The Hallelujah chorus came next, though lag made it difficult to sing along.
Lots of Chinese people, too. Talked to a guy in Chongqing for a while. I've found that having a guitar or some other prop (a stuffed chicken also worked) attracts more interest than if I'm just sitting there.