take a look at nyclondon.com. (the British B&W magazine has it as the photoblog of the month btw). all of rob's street work in nyc was done with a leica m6 or a plaubel-makina 6x7 rangefinder camera. the photographs are suberb and he's been able to be very direct in his images. in the current climate, it seems extremely prudent to be as unobtrusive as possble. good luck.
(there's a new film about to be released called "Paparazzi" which exploits the absolute worst possible sins of an already disreputable endeavor. it's going to make it even tougher for the average street shooter to be regarded as a harmless chronicler of quotidian subjects than ever. maybe you should consider just getting an 8x10 and shooting waterfalls ;-)