The fastest growing craze in puzzles these days is Sudoku, a 9-grid number puzzle. has a version you can play online–three new puzzles every day. Waste your time and stave off Alzheimer’s, all in one blow!

Daily Sudoku
The object of this puzzle (popular in Japan, and spreading through the UK and the U.S.) is “to insert the numbers in the boxes to satisfy only one condition: each row, column and 3×3 box must contain the digits 1 through 9 exactly once.” The website includes a daily puzzle, a puzzle archive (back to January 2005), a FAQ, a message board, and a daily puzzle for children. From the author of a sudoku puzzle book.

Sudoku Classic
Archive of sudoku puzzles, published six days a week, ranging from easy to difficult. Sudoku (a puzzle popular in Japan, and now gaining popularity in the U.K. and the U.S.) has one rule, “place the numbers from 1 to 9 in each row, in each column and each 3×3 box.” From the Guardian Unlimited, the online companion to the British newspaper The Guardian.

You can also find a Sudoku puzzle in the Dallas Morning News every day.