Upon meeting Will Gibson, two things become abundantly clear: this man knows his computers and he knows his Sudoku.
For those not familiar with the puzzle phenomenon whose popularity has grown exponentially since 2005 when it left puzzle books and started hitting the mainstream, Sudoku is a puzzle involving nine blocks each divided into nine squares. Some of the 81 squares are left blank, while others contain a clue consisting of a single digit from one to nine. The goal of the puzzle is to fill in the blank portions of the puzzle such that each row, column and block contains each of the numbers one through nine only once.
Photo from flickr creative commons. By Paul Downey