I do as Robert C does; bungee the box to my rear rack. My closest pizza place is a Panago - a medium pepperoni is $12, but once they charge you $3 for the delivery, and I tip the delivery guy $2 or $3, my pizza has gone up 50% in price.
I like the quizzical looks I get when I walk out to my bike with as pizza box, as though I were moving a piano with a Red Flyer wagon.
I didn't think Little Ceasars could be legally called pizza. Isn't it "Pizza type food"

Even calling it food is a stretch.