Tangrams are really fun especially if you like brain teasers. There is a long and ancient history involved with Tangrams. Essentially they are based on geometric principles. You have 6 blocks or so and you have to configure them into a specified shape (shapes are illustrated in a booklet). The puzzles are even more exciting if you do it with friends (each with their own Tangram set) and see who can configure the shape the fastest. Great gift idea. (via Amazon)