I got a very interesting book as a gift this year, "Tangram Puzzles" by Chris Crawford. It describes an ancient puzzle game, Tangrams, and contains many puzzles to solve. It even comes with the gamepieces. After my initial excitement subdued :), I just had to share it with others! And what better medium, than a Java applet! :) Now I have finished an early prototype of the game, and some of the playability is there: pieces can be dragged and rotated, plus I started on some overlapping checking.