This week on the Post: giving books at Christmas. Icelanders celebrate Jolabokaflod ('Christmas Book Flood') on Christmas Eve, a tradition whose origins are unclear but which was popularised when paper was one of the few unrestricted commodities in the 1940s. Books are given as presents, and it's part of the tradition to start reading immediately, often with hot chocolate or beer. No wonder books are the most popular Christmas gift in Iceland. (Hallgrímskirkja in Reykjavik, completed 1986.)