I first came in contact with Sudoku a few years ago, back when I was a student. I traveled a lot, about three hours one-way at least twice a month, and it was a real pleasure "not" to waste my time just staring in the moving environment, although even that can be fun sometimes, but it gets a bit dull after the first couple of trips and then it simply makes you asleep :)
Few months ago I got obsessed with it, again, I've started solving Sudoku puzzles in a specialized Sudoku magazines (daily newspapers puzzles weren't enough anymore), and it's become a real office mind-stimulating treatment... Try making a short Sudoku-solving break every time you're coding something, in a short time you'll find algorithms leaking out of your brains, and coding faster than you've ever had :)... No, seriously, it has some strange positive influence on your (or mine at least) logic, maybe because there is so much logic in it... even though it's so simple game.
I wanted to go deeper this time... you know "Set the Controls for the Heart of the Sun", find out more about it, reach for its "essence", build an algorithm or two and then do a bit of coding. It sounds like a story so far ain't it :), yet this post is intended to be a showcase of some approaches and algorithms for creating a Sudoku puzzles and games. So let's get technical...