How do I flip an egg when preparing it "over easy"? I tend to break a lot of yolks when preparing eggs over easy. I also can't do it too fast, making it hard to cook multiple eggs at once (they tend to overcook). 

Sometimes the spatula I'm using doesn't want to slide under the egg very easily. Is there anything special about the type of spatula or special preparation with the pan or eggs that might make this harder or easier?
The best thing I've figured out about turning eggs is: do not do it too early. You need to wait for the cooked part of the egg to develop a strong texture before it will support its own weight. It's very difficult to turn a floppy, soft egg, where it's comparatively easy to flip an egg that has been cooked more completely on one side. I also use a relatively high heat, as this "crisps" the cooked surface. It also makes the egg more attractive.

The spatula you use can make a difference, also, though I believe this is minor. The spatula you want is a plastic one with a relatively thin, flexible blade. The really heavy spatulas tend to be too tall, in my experience, and push the egg rather than sneak under it.