Can I reheat leftover pizza in a microwave oven?

Microwaves tend to draw moisture from foods, pizzas included. To prevent pizza from becoming hard and dry, fill a cup with water half way up and place it in the back of the microwave. (If the microwave has a rotating plate, place the cup in a back corner of the microwave.) Place pizza on a microwave-safe plate and heat it for 25-35 seconds. Times may vary, depending on the size of the microwave and how hot you want the pizza.
 
Pizzas can  also be reheated in the oven. Reheat the pizza at a temperature of 350°F. Don't cover the pizza, or it will turn soggy. Reheat only 10 minutes or so. After that, the pizza will dry out.
 
Source(s):
Ehow.com "How to Reheat Leftover Pizza"
Practicallyedible.com "Pizza"