Very interesting topic.
Most of the time I shoot in plain sight. Not exactly "in your face", but with three motor driven cameras, vest and large bag hanging off one shoulder, I can't be called unobtrusive or stealthy.
Additionally, when I'm shooting street or homeles people, I usually ask for permission simply because I feel they are deserving of respect and the option of refusing permission should they so choose. By then taking the time to converse with them including introducing myself, shaking hands and
never standing over them if they are sitting or lying on the sidewalk, I often put them enough at ease to get candid images.
Of course when the need arises, I've also learned to be stealthy, and by using wide lenses set to hyperfocus shot without lookin through the viewfinder, or by simply shooting quickly, (my cameras are all manual focus, but experience and practice have made me pretty good at sniping) I can usually get what I want.
The majority of the time I use SLR's, but for the last year I've also been using an S3 rangefinder.
For anyone who cares to take a peek and see some of my photos:
www.nikongear.com/alb/thumbnails.php?album=153