How to defrost frozen pizza dough quickly?
If you dough is a disc shape:
When I worked as a pizza cook at a popular fast food pizza place, we would put our dough still frozen into what we called a proofer. It was basically a heated cabinet around 130 F. It would defrost and have it's final rise in there. After that we would stretch to make the pizza. You could probably replicate this by putting your dough into a covered pan in the oven without preheating on "low" or "warm". You would also want to put a bowl of boiling water in there to add steam. Just make sure it doesn't burn or get up to temperature. You may want water or oil in there with it so it doesn't dry out.

If you dough is in a ball:
I do this for other frozen foods, but haven't tried it on dough before.  Put it in a sealed plastic bag and leave it in warm water. I like to leave it with a constant stream of warm water flowing over the object so the water stays warm. The heat should defrost it and the plastic should keep it dry.