In Japan they have square watermelons.

They get square watermelons by growing them inside of square glass cases. That way they can fit easily into a refrigerator, and you can stack things on them. Square watermelons are expensive though (10,000 yen or about $82). Compare that to regular round watermelons which cost about $15-20 in Japan.Farmers in the southern Japanese town of Zentsuji have figured out how to grow their watermelons so they turn out square. It's not a fad. The technique actually has practical applications. "The reason they're doing this in Japan is because of lack of space," said Samantha Winters of the National Watermelon Promotion Board in Orlando, Florida. A fat, round watermelon can take up a lot of room in a refrigerator, and the usually round fruit often sits awkwardly on refrigerator shelves. "You can find two-inch cubes" in groceries, Winters said. "They have watermelon that's cut in quarters and halves. And you can find clamshell containers with fresh-cut watermelon in there as well." Watermelon also can be pureed and poured into ice-cube trays for freezing.