Not sure what you mean by cases that "flip" but I am using BookBook by TwelveSouth. It's leather, it holds the iPhone 4S and a few credit cards, license, some cash, and it flips. Everything is accessible from within the case except the rear camera but that is easy to push the phone up out of the case to use. If you take lots of pics this might not be the case for you.
Try daydeal.com. I've used them before and they're delivery is pretty quick. They have a few styles of flip leather cases. Here's the link: daydeal cases