Since 1999, April 1st has been celebrated by increasing numbers of libraries and bookstores with "Edible Book Festivals." According to International Edible Books Festival, the date was chosen because:
April 1st is the birthday of French gastronome Jean-Anthelme Brillat-Savarin (1755-1826), famous for his book Physiologie du goût, a witty meditation on food. April fools' day is also the perfect day to eat your words and play with them as the "books" are consumed on the day of the event. This ephemeral global banquet, in which anyone can participate, is shared by all on the internet and allows everyone to preserve and discover unique bookish nourishments. This festival is a celebration of the ingestion of culture and a way to concretely share a book; it is also a deeper reflexion on our attachment to food and our cultural differences.
I have not found sites posting pictures of this year's entries yet, but for past years' constructions, among many others see: