Day-old pizza is God's gift to college students, starving artists and anyone who thought it was a brilliant idea to order that extra-large double-meat at 2 a.m. after coming home from the bar, only to go sleepy-peepy halfway through the first slice. But while cold pizza is a bona fide breakfast of champions, what about room-temperature pizza? Will you get sick if you throw down a few slices of the pepperoni that sat in a greasy cardboard box next to your bed for the last eight hours? The official answer — don't risk it. The United States Department of Agriculture...