WIRED Video: Street Portraiture
It has nothing to do with flash, actually. In fact, it is all available light (in shade) and shot on taped-up white seamless. In this configuration, the open sun area behind you is almost like a huge, on-axis soft box.
But this isn't about the lighting. It is a good primer on overcoming your shyness of photographing others -- and how to interact with them in a quick, fluid environment. Something I suspect many people reading this site will appreciate.
FYI, the photographer is Clay Enos, and you can see more of his work here. And on top of that, he is a pretty consistent blogger, too.
Thanks much for the tips, Clay. And ditto to WIRED.com, for making the video embeddable.