Just a small, cheap 35mm camera should do. I take an average quality digital camera. I also turn off the flash, so not to draw any attention. I also take small, pocket size cameras that can be easily hidden. So when I see something that looks interesting, I turn on my digital camera (or leave it on), wait for it to charge, take the camera out of my pocket, and take the picture. That means that my camera can be out of my pocket for only 4 to 15 seconds. Good for candid street shots.
One trick is to look one direction, like I am taking a picture in that direction, but really take a picture of somebody off to the side. I always use wide-angle lens as much as possible
Photo Equipment: Bring your camera, but don't bring all of your expensive camera equipment. Keep it simple and not too flashy so you don't attract the thieves.