A jack-o'-lantern is typically a carved pumpkin. It is associated chiefly with the holiday of Samhain and Halloween and was named after the phenomenon of strange light flickering over peat bogs, called ignis fatuus or jack-o'-lantern. In a jack-o'-lantern, typically the top is cut off, and the inside flesh then scooped out; an image, usually a monstrous face, is carved out, and the lid replaced. It is typically seen during Halloween. Read this and you will know more : http://en.wikipedia.org/wiki/Jack-o%27-lantern

because it is best thing to do with a pumpkin in the west. for example in Turkey we make delicious desserts with pumpkins.